code: function looksLikeExport(astNode) {
      return astNode.type === "ExportDefaultDeclaration" || astNode.type === "ExportNamedDeclaration" ||
          astNode.type === "ExportAllDeclaration" || astNode.type === "ExportSpecifier";
  }
docs: Check to see if its a ES6 export declaration.
  @param {ASTNode} astNode An AST node.
  @returns {boolean} whether the given node represents an export declaration.
  @private