@Nullable
  private PyExpression resolveKeywordPercent(@NotNull PyExpression expression, @NotNull String key) {
    final PyExpression containedExpr = PyPsiUtils.flattenParens(expression);
    if (PsiTreeUtil.instanceOf(containedExpr, PyDictLiteralExpression.class)) {
      final Ref<PyExpression> resolvedRef = getElementFromDictLiteral((PyDictLiteralExpression)containedExpr, key);
      return resolvedRef != null ? resolvedRef.get() : containedExpr;
    }
    else if (PsiTreeUtil.instanceOf(containedExpr, PyLiteralExpression.class, PySetLiteralExpression.class, PyListLiteralExpression.class,
                                    PyTupleExpression.class)) {
      return null;
    }
    else if (containedExpr instanceof PyCallExpression) {
      if (myChunk.getMappingKey() != null) {
        Ref<PyExpression> elementRef = resolveDictCall((PyCallExpression)containedExpr, myChunk.getMappingKey(), true);
        if (elementRef != null) return elementRef.get();
      }
    }
    return containedExpr;
  }
@Nullable
  private PyExpression resolveKeywordPercent(@NotNull PyExpression expression, @NotNull String key)