diff --git a/src/environment/RuntimeEnvironment.java b/src/environment/RuntimeEnvironment.java
index 628e20a..de0030f 100644
--- a/src/environment/RuntimeEnvironment.java
+++ b/src/environment/RuntimeEnvironment.java
@@ -21,7 +21,7 @@ public class RuntimeEnvironment {
     private ErrorManager errorManager;
 
     private RuntimeEnvironment() {}
-    
+
     public void setInputName(String inputName) {
         this.inputName = inputName;
     }
@@ -45,11 +45,11 @@ public class RuntimeEnvironment {
     public void setErrorTerminationFunction(Runnable errorTerminationFunction) {
         this.errorTerminationFunction = errorTerminationFunction;
     }
-    
+
     public void setErrorManager(ErrorManager errorManager) {
         this.errorManager = errorManager;
     }
-    
+
     public String getInputName() {
         return inputName;
     }
@@ -73,7 +73,7 @@ public class RuntimeEnvironment {
     public void terminateExceptionally() {
         errorTerminationFunction.run();
     }
-    
+
     public ErrorManager getErrorManager() {
         return errorManager;
     }
diff --git a/src/token/TokenFactoryImpl.java b/src/token/TokenFactoryImpl.java
index eb22e69..14c8a84 100644
--- a/src/token/TokenFactoryImpl.java
+++ b/src/token/TokenFactoryImpl.java
@@ -10,7 +10,7 @@ public class TokenFactoryImpl implements TokenFactory {
     public Token createToken(String text, FilePosition position) {
         if (text.length() == 0)
             throw new EmptyTokenTextException(position);
-            
+
         char firstCharacter = text.charAt(0);
 
         switch (firstCharacter) {
diff --git a/test/environment/RuntimeEnvironmentTester.java b/test/environment/RuntimeEnvironmentTester.java
index 0241c01..fa87a7c 100644
--- a/test/environment/RuntimeEnvironmentTester.java
+++ b/test/environment/RuntimeEnvironmentTester.java
@@ -22,35 +22,35 @@ public class RuntimeEnvironmentTester {
 
     @Before
     public void setUp() {
-        this.indicatorSet = new HashSet<>();
+        indicatorSet = new HashSet<>();
     }
 
     @Test
     public void assignInputName() {
-        this.environment.setInputName("test");
+        environment.setInputName("test");
 
-        assertEquals("test", this.environment.getInputName());
+        assertEquals("test", environment.getInputName());
     }
 
     @Test
     public void assignInput() {
-        this.environment.setInput(System.in);
+        environment.setInput(System.in);
 
-        assertEquals(System.in, this.environment.getInput());
+        assertEquals(System.in, environment.getInput());
     }
 
     @Test
     public void assignOutput() {
-        this.environment.setOutput(System.out);
+        environment.setOutput(System.out);
 
-        assertEquals(System.out, this.environment.getOutput());
+        assertEquals(System.out, environment.getOutput());
     }
 
     @Test
     public void assignErrorOutput() {
-        this.environment.setErrorOutput(System.err);
+        environment.setErrorOutput(System.err);
 
-        assertEquals(System.err, this.environment.getErrorOutput());
+        assertEquals(System.err, environment.getErrorOutput());
     }
 
     @Test
@@ -72,9 +72,9 @@ public class RuntimeEnvironmentTester {
     @Test
     public void assignErrorManager() {
         ErrorManager errorManager = new ErrorManager();
-        this.environment.setErrorManager(errorManager);
+        environment.setErrorManager(errorManager);
 
-        assertEquals(errorManager, this.environment.getErrorManager());
+        assertEquals(errorManager, environment.getErrorManager());
     }
 
 }
diff --git a/test/error/ErrorManagerTester.java b/test/error/ErrorManagerTester.java
index 2882662..36929f3 100644
--- a/test/error/ErrorManagerTester.java
+++ b/test/error/ErrorManagerTester.java
@@ -19,11 +19,16 @@ public class ErrorManagerTester {
     private Set<String> indicatorSet;
     private ByteArrayOutputStream errorOutputStream;
     private ByteArrayOutputStream outputStream;
+    private RuntimeEnvironment environment;
+
+    public ErrorManagerTester() {
+        this.environment = RuntimeEnvironment.getInstance();
+    }
 
     private ErrorManager createErrorManagerWithIndicators() {
-        RuntimeEnvironment.getInstance().setErrorTerminationFunction(() -> indicatorSet.add(TERMINATED));
-        RuntimeEnvironment.getInstance().setErrorOutput(new PrintStream(errorOutputStream));
-        RuntimeEnvironment.getInstance().setOutput(new PrintStream(outputStream));
+        environment.setErrorTerminationFunction(() -> indicatorSet.add(TERMINATED));
+        environment.setErrorOutput(new PrintStream(errorOutputStream));
+        environment.setOutput(new PrintStream(outputStream));
 
         return new ErrorManager();
     }
@@ -71,9 +76,9 @@ public class ErrorManagerTester {
 
     @Before
     public void setUp() {
-        this.indicatorSet = new HashSet<>();
-        this.errorOutputStream = new ByteArrayOutputStream();
-        this.outputStream = new ByteArrayOutputStream();
+        indicatorSet = new HashSet<>();
+        errorOutputStream = new ByteArrayOutputStream();
+        outputStream = new ByteArrayOutputStream();
     }
 
     @Test
diff --git a/test/function/builtin/LOADTester.java b/test/function/builtin/LOADTester.java
index 4c37c8a..4dfff24 100644
--- a/test/function/builtin/LOADTester.java
+++ b/test/function/builtin/LOADTester.java
@@ -16,6 +16,11 @@ public class LOADTester {
 
     private ByteArrayOutputStream outputStream;
     private ByteArrayOutputStream errorOutputStream;
+    private RuntimeEnvironment environment;
+
+    public LOADTester() {
+        this.environment = RuntimeEnvironment.getInstance();
+    }
 
     private void assertWarningMessagePrinted() {
         assertTrue(outputStream.toByteArray().length > 0);
@@ -34,11 +39,12 @@ public class LOADTester {
 
     @Before
     public void setUp() {
-        this.outputStream = new ByteArrayOutputStream();
-        this.errorOutputStream = new ByteArrayOutputStream();
-        RuntimeEnvironment.getInstance().setOutput(new PrintStream(outputStream));
-        RuntimeEnvironment.getInstance().setErrorOutput(new PrintStream(errorOutputStream));
-        RuntimeEnvironment.getInstance().setErrorManager(new ErrorManager());
+        outputStream = new ByteArrayOutputStream();
+        errorOutputStream = new ByteArrayOutputStream();
+
+        environment.setOutput(new PrintStream(outputStream));
+        environment.setErrorOutput(new PrintStream(errorOutputStream));
+        environment.setErrorManager(new ErrorManager());
     }
 
     @Test
diff --git a/test/function/builtin/PRINTTester.java b/test/function/builtin/PRINTTester.java
index dc7baea..2bce16d 100644
--- a/test/function/builtin/PRINTTester.java
+++ b/test/function/builtin/PRINTTester.java
@@ -21,7 +21,7 @@ public class PRINTTester {
 
     @Before
     public void setUp() {
-        this.outputStream = new ByteArrayOutputStream();
+        outputStream = new ByteArrayOutputStream();
         RuntimeEnvironment.getInstance().setOutput(new PrintStream(outputStream));
     }
 
diff --git a/test/function/builtin/special/DEFUNTester.java b/test/function/builtin/special/DEFUNTester.java
index 49e36de..c3fae13 100644
--- a/test/function/builtin/special/DEFUNTester.java
+++ b/test/function/builtin/special/DEFUNTester.java
@@ -15,6 +15,11 @@ import table.FunctionTable;
 public class DEFUNTester {
 
     private ByteArrayOutputStream outputStream;
+    private RuntimeEnvironment environment;
+
+    public DEFUNTester() {
+        this.environment = RuntimeEnvironment.getInstance();
+    }
 
     private void assertSomethingPrinted() {
         assertTrue(outputStream.toByteArray().length > 0);
@@ -22,9 +27,11 @@ public class DEFUNTester {
 
     @Before
     public void setUp() {
-        this.outputStream = new ByteArrayOutputStream();
-        RuntimeEnvironment.getInstance().setOutput(new PrintStream(outputStream));
-        RuntimeEnvironment.getInstance().setErrorManager(new ErrorManager());
+        outputStream = new ByteArrayOutputStream();
+
+        environment.setOutput(new PrintStream(outputStream));
+        environment.setErrorManager(new ErrorManager());
+
         FunctionTable.reset();
     }