code: function is$$ (node) {
    return node.callee.name === '$$' || (node.callee.property && node.callee.property.name === '$$')
  }
docs: Checks if a given node is an ElementArrayFinder represented by $$() callee - both nested and not
  
  @param {ASTNode} node - A node to check.
  @returns {boolean}