code: def _apply_missing_flagdef_attrs(flagdef, existing, opdef, source):
      """Applies missing flag attributes in `flagdef` to `existing`.
  
      A missing attribute is an attribute with value None in `existing`.
  
      Only applies the attributes listed in `MERGE_FLAGDEF_ATTRS`. This
      list corresponds to the set of all possible flag attributes in
      generated flags.
      """
      _apply_merge_attrs(flagdef, existing)
      _apply_force_attrs(flagdef, existing, opdef, source)
  
file_path: guildai/guild/plugins/resource_flags.py
imports: import logging
  from guild import guildfile
  from guild import op_dep
  from guild import plugin
label_desc: Use image node_id 10 for calling a global function with example usage: _apply_missing_flagdef_attrs(flagdef, existing, opdef, source) without return types