code: public FunctionLibrary getLibraryForPrefix(String functionPrefix) {
          for (int i = 0; i < functionLibraries.size(); i++) {
              if (((FunctionLibrary)functionLibraries.get(i)).getPrefix().equals(functionPrefix)) {
                  return (FunctionLibrary)functionLibraries.get(i);
              }
          }
  
          throw new NoSuchFunctionLibraryException("Can not find function library for prefix " + functionPrefix);
      }
docs: Get library for function prefix.
  @param functionPrefix to be searched for
  @return FunctionLibrary instance