code: def prefix_loader(filesystem_loader, dict_loader):
      """returns a PrefixLoader"""
      return loaders.PrefixLoader(
          {"a": filesystem_loader, "b": dict_loader}
      )
  
file_path: catboost/contrib/python/Jinja2/py2/tests/conftest.py
imports: import os
  import pytest
  from jinja2 import Environment
  from jinja2 import loaders
  from jinja2.utils import have_async_gen
label_desc: Use image node_id 8 for calling a global function with example usage: prefix_loader(filesystem_loader, dict_loader) and returns: loaders