code: def metatarget(f):
      f.bjam_signature = (
          ["name"],
          ["sources", "*"],
          ["requirements", "*"],
          ["default_build", "*"],
          ["usage_requirements", "*"],
      )
      return f
  
imports: import bjam
  import re
  import types
  from itertools import groupby
label_desc: Use image node_id 7 for calling a global function with example usage: metatarget(f) and returns: f