code: function getLibraryCallContractName (funcCall) {
    if (!isLibraryCall(funcCall)) throw new Error('staticAnalysisCommon.js: not an this library call Node')
    return new RegExp(basicRegex.LIBRARYTYPE).exec(funcCall.children[0].attributes.type)[1]
  }
docs: Returns the name of the library called, Throws on wrong node.
  Example:
  library set{...}
  contract foo {
  ...
  function () { set.union() => set}
  @funcCall {ASTNode} function call node
  @return {string} name of the lib defined