old_contents: """
  Loader for plain old Mybuild files.
  """
  
  __author__ = "Eldar Abusalimov"
  __date__ = "2013-07-05"
  
  
  from _compat import *
  
  from mylang import my_compile
  from mylang import runtime
  from nsloader.pyfile import PyFileLoader
  
  
  class MyFileLoader(PyFileLoader):
      """Loads My-files using myfile parser/linker."""
  
      MODULE = 'Myfile'
  
      @classmethod
      def init_ctx(cls, importer, initials):
          exec_ctx = runtime.ProxifyingExecContext()
          builtins = runtime.prepare_builtins(exec_ctx)
          super_ctx = super(MyFileLoader, cls).init_ctx(importer, initials)
  
          return exec_ctx, builtins, super_ctx
  
      @classmethod
      def exit_ctx(cls, loader_ctx):
          exec_ctx, _, _ = loader_ctx
          exec_ctx.resolve_all()
  
      def __init__(self, loader_ctx, fullname, path):
          _, self.builtins, super_ctx = loader_ctx
          super(MyFileLoader, self).__init__(super_ctx, fullname, path)
  
      def get_code(self, fullname):
          source_path = self.get_filename(fullname)
          source_bytes = self.get_data(source_path)
  
          return my_compile(source_bytes, source_path, 'exec')
  
      def _init_module(self, module):
          module.__dict__['__builtins__'] = self.builtins
          super(MyFileLoader, self)._init_module(module)
  
  
  
new_contents: """
  Loader for plain old Mybuild files.
  """
  
  __author__ = "Eldar Abusalimov"
  __date__ = "2013-07-05"
  
  
  from _compat import *
  
  from mylang import my_compile
  from mylang import runtime
  from nsloader import pyfile
  
  
  class MyFileLoader(pyfile.PyFileLoader):
      """Loads My-files using myfile parser/linker."""
  
      MODULE = 'Myfile'
  
      def get_code(self, fullname):
          source_path = self.get_filename(fullname)
          source_bytes = self.get_data(source_path)
  
          return my_compile(source_bytes, source_path, 'exec')
  
      def _init_module(self, module):
          module.__dict__['__builtins__'] = runtime.builtins
          super(MyFileLoader, self)._init_module(module)
  
  
subject: simplify (remove init_ctx/exit_ctx)