private static PsiMethodCallExpression findCandidateToRemove(PsiMethodCallExpression mapCall) {
      final PsiMethodCallExpression filterCall = getQualifierMethodCall(mapCall);
      if (!STREAM_FILTER.test(filterCall)) return null;
      return findSingleCalledMethod(filterCall.getArgumentList().getExpressions()[0]);
    }
private static PsiMethodCallExpression findCandidateToRemove(PsiMethodCallExpression mapCall)