diff --git a/python/pydevSrc/src/com/jetbrains/python/debugger/pydev/MultiProcessDebugger.java b/python/pydevSrc/src/com/jetbrains/python/debugger/pydev/MultiProcessDebugger.java
index 39f2cbc159c8..d6cdc5d6dcd1 100644
--- a/python/pydevSrc/src/com/jetbrains/python/debugger/pydev/MultiProcessDebugger.java
+++ b/python/pydevSrc/src/com/jetbrains/python/debugger/pydev/MultiProcessDebugger.java
@@ -320,7 +320,7 @@ public class MultiProcessDebugger implements ProcessDebugger {
 
     List<PyThreadInfo> threads = collectAllThreads();
 
-    if (myOtherDebuggers.size() > 0) {
+    if (!myOtherDebuggers.isEmpty()) {
       //here we add process id to thread name in case there are more then one process
       return Collections.unmodifiableCollection(Collections2.transform(threads, t -> {
         if (t == null) return null;
@@ -339,12 +339,11 @@ public class MultiProcessDebugger implements ProcessDebugger {
   }
 
   private List<PyThreadInfo> collectAllThreads() {
-    List<PyThreadInfo> result = new ArrayList<>();
 
-    result.addAll(myMainDebugger.getThreads());
+    List<PyThreadInfo> result = new ArrayList<>(myMainDebugger.getThreads());
 
-    //collect threads and add them to registry to faster access
-    //we don't register mainDebugger as it is default if there is no mapping
+    // Collect threads and add them to registry to faster access
+    // we don't register mainDebugger as it is default if there is no mapping.
     for (RemoteDebugger d : myOtherDebuggers) {
       result.addAll(d.getThreads());
       for (PyThreadInfo t : d.getThreads()) {
@@ -636,10 +635,6 @@ public class MultiProcessDebugger implements ProcessDebugger {
     }
   }
 
-  public void removeCloseListener(RemoteDebuggerCloseListener listener) {
-    myMainDebugger.removeCloseListener(listener);
-  }
-
   public void addOtherDebuggerCloseListener(DebuggerProcessListener otherDebuggerCloseListener) {
     myOtherDebuggerCloseListener.add(otherDebuggerCloseListener);
   }
diff --git a/python/src/com/jetbrains/python/debugger/PyDebugProcess.java b/python/src/com/jetbrains/python/debugger/PyDebugProcess.java
index b8a7d5cba8e5..cdba056e13db 100644
--- a/python/src/com/jetbrains/python/debugger/PyDebugProcess.java
+++ b/python/src/com/jetbrains/python/debugger/PyDebugProcess.java
@@ -27,7 +27,6 @@ import com.intellij.openapi.progress.ProgressIndicator;
 import com.intellij.openapi.progress.ProgressManager;
 import com.intellij.openapi.progress.Task;
 import com.intellij.openapi.project.Project;
-import com.intellij.openapi.util.Key;
 import com.intellij.openapi.util.NlsActions;
 import com.intellij.openapi.util.NlsContexts.ProgressText;
 import com.intellij.openapi.util.NlsContexts.ProgressTitle;
@@ -287,7 +286,7 @@ public class PyDebugProcess extends XDebugProcess implements IPyDebugProcess, Pr
     // which causes the process to finish with a non-zero exit code or the `KeyboardInterrupt` exception.
     // This issue happens frequently with multiprocess debugging.
     getProcessHandler().waitFor();
-    handleStop(); //in case of normal debug we stop the session
+    handleStop(); // In case of normal debug, we stop the session
   }
 
   protected void handleStop() {
@@ -839,11 +838,11 @@ public class PyDebugProcess extends XDebugProcess implements IPyDebugProcess, Pr
   public XValueChildrenList loadFrame(@Nullable final XStackFrame contextFrame) throws PyDebuggerException {
     final PyStackFrame frame = contextFrame == null ? currentFrame() : (PyStackFrame)contextFrame;
     synchronized (myFrameCacheObject) {
-      //do not reload frame every time it is needed, because due to bug in pdb, reloading frame clears all variable changes
+      // Do not reload frame every time it is needed, because due to a bug in pdb, reloading frame clears all variable changes.
       if (!myStackFrameCache.containsKey(frame.getThreadFrameId())) {
         XValueChildrenList values = myDebugger.loadFrame(frame.getThreadId(), frame.getFrameId(), ProcessDebugger.GROUP_TYPE.DEFAULT);
         // Could be null when the current function is called for a thread that is already dead.
-        // In this case a new element shouldn't be added to myStackFrameCache
+        // In this case, a new element shouldn't be added to myStackFrameCache.
         if (values == null) {
           return null;
         }