static boolean doesFlatMapCallCollectionStream(PsiMethodCallExpression flatMapCall) {
    PsiElement function = flatMapCall.getArgumentList().getExpressions()[0];
    if (function instanceof PsiMethodReferenceExpression methodRef) {
      if (!STREAM_METHOD.equals(methodRef.getReferenceName())) return false;
      PsiMethod method = ObjectUtils.tryCast(methodRef.resolve(), PsiMethod.class);
      if (method != null && STREAM_METHOD.equals(method.getName()) && method.getParameterList().isEmpty()) {
        final PsiClass containingClass = method.getContainingClass();
        if (containingClass != null && CommonClassNames.JAVA_UTIL_COLLECTION.equals(containingClass.getQualifiedName())) {
          return true;
        }
      }
    }
    else if (function instanceof PsiLambdaExpression) {
      PsiExpression expression = extractLambdaReturnExpression((PsiLambdaExpression)function);
      return expression instanceof PsiMethodCallExpression && COLLECTION_STREAM.test((PsiMethodCallExpression)expression);
    }
    return false;
  }
static boolean doesFlatMapCallCollectionStream(PsiMethodCallExpression flatMapCall)