code: function isShadowed(scope, node) {
      const reference = findReference(scope, node);
  
      return reference && reference.resolved && reference.resolved.defs.length > 0;
  }
docs: Checks if the given identifier node is shadowed in the given scope.
  @param {Object} scope The current scope.
  @param {string} node The identifier node to check
  @returns {boolean} Whether or not the name is shadowed.