`verboseOnly` added to call some code only if appropriate env var is set.

Some checks may be heavy, but required to debug hard-to-find bugs. You may run code with out them, and enable em with   ``_PYCHARM_VERBOSE_MODE``

python/src/com/jetbrains/python/psi/PyUtil.java

@@ -858,6 +858,16 @@ public class PyUtil {
     return result;
   }
 
+  /**
+   * Executes code only if <pre>_PYCHARM_VERBOSE_MODE</pre> is set in env (which should be done for debug purposes only)
+   * @param runnable code to call
+   */
+  public static void verboseOnly(@NotNull final Runnable runnable) {
+    if (System.getenv().get("_PYCHARM_VERBOSE_MODE") != null) {
+      runnable.run();
+    }
+  }
+
   public static class KnownDecoratorProviderHolder {
     public static PyKnownDecoratorProvider[] KNOWN_DECORATOR_PROVIDERS = Extensions.getExtensions(PyKnownDecoratorProvider.EP_NAME);
 

python/src/com/jetbrains/python/psi/impl/PyBaseElementImpl.java

@@ -17,7 +17,6 @@ package com.jetbrains.python.psi.impl;
 
 import com.intellij.extapi.psi.StubBasedPsiElementBase;
 import com.intellij.lang.ASTNode;
-import com.intellij.openapi.application.ApplicationManager;
 import com.intellij.openapi.util.TextRange;
 import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.psi.*;
@@ -32,6 +31,7 @@ import com.jetbrains.python.PythonLanguage;
 import com.jetbrains.python.psi.PyElement;
 import com.jetbrains.python.psi.PyElementVisitor;
 import com.jetbrains.python.psi.PyReferenceOwner;
+import com.jetbrains.python.psi.PyUtil;
 import com.jetbrains.python.psi.resolve.PyResolveContext;
 import com.jetbrains.python.psi.types.TypeEvalContext;
 import org.jetbrains.annotations.NotNull;
@@ -71,10 +71,7 @@ public class PyBaseElementImpl<T extends StubElement> extends StubBasedPsiElemen
   }
 
   public void accept(@NotNull PsiElementVisitor visitor) {
-    if (ApplicationManager.getApplication().isUnitTestMode()) {
-      // Good check, but too slow for production
-      PyPsiUtils.assertValid(this);
-    }
+    PyUtil.verboseOnly(() -> PyPsiUtils.assertValid(this));
     if (visitor instanceof PyElementVisitor) {
       acceptPyVisitor(((PyElementVisitor)visitor));
     }

python/src/com/jetbrains/python/psi/impl/PyCallExpressionHelper.java

@@ -462,9 +462,7 @@ public class PyCallExpressionHelper {
         final PsiPolyVariantReference reference = ((PyReferenceExpression)callee).getReference(resolveContext);
         final List<PyType> members = new ArrayList<PyType>();
         for (PsiElement target : PyUtil.multiResolveTopPriority(reference)) {
-          if (ApplicationManager.getApplication().isUnitTestMode()) {
-            PyPsiUtils.assertValid(target);
-          }
+          PyUtil.verboseOnly(() ->PyPsiUtils.assertValid(target));
           if (target != null) {
             final Ref<? extends PyType> typeRef = getCallTargetReturnType(call, target, context);
             if (typeRef != null) {

python/src/com/jetbrains/python/psi/impl/PyEvaluator.java

@@ -59,9 +59,7 @@ public class PyEvaluator {
     if (expr == null || myVisited.contains(expr)) {
       return null;
     }
-    if (ApplicationManager.getApplication().isUnitTestMode()) {
-      PyPsiUtils.assertValid(expr);
-    }
+    PyUtil.verboseOnly(() ->PyPsiUtils.assertValid(expr));
     myVisited.add(expr);
     if (expr instanceof PyParenthesizedExpression) {
       return evaluate(((PyParenthesizedExpression)expr).getContainedExpression());

python/src/com/jetbrains/python/psi/resolve/ResolveImportUtil.java

@@ -116,9 +116,7 @@ public class ResolveImportUtil {
 
   @NotNull
   public static List<RatedResolveResult> multiResolveImportElement(PyImportElement importElement, @NotNull final QualifiedName qName) {
-    if (ApplicationManager.getApplication().isUnitTestMode()) {
-      PyPsiUtils.assertValid(importElement);
-    }
+    PyUtil.verboseOnly(() ->PyPsiUtils.assertValid(importElement));
     final PyStatement importStatement = importElement.getContainingImportStatement();
     if (importStatement instanceof PyFromImportStatement) {
       return resolveNameInFromImport((PyFromImportStatement)importStatement, qName);