parameters: (mod, submod, fullname, subname)
return_statement: return
docstring: mod.{subname} = submod
docstring_summary: mod.{subname} = submod
docstring_tokens: mod . { subname } = submod
function: def add_submodule(mod, submod, fullname, subname):
      """mod.{subname} = submod"""
      if mod is None:
          return #Nothing to do here.
  
      if submod is None:
          submod = sys.modules[fullname]
  
      setattr(mod, subname, submod)
  
      return
function_tokens: def add_submodule ( mod , submod , fullname , subname ) : if mod is None : return #Nothing to do here. if submod is None : submod = sys . modules [ fullname ] setattr ( mod , subname , submod ) return