code: def doc(ctx):
      """Build the documentation"""
      header(doc.__doc__)
      with ctx.cd(os.path.join(ROOT, "doc")):
          ctx.run("make html", pty=True)
  
imports: from __future__ import unicode_literals, absolute_import
  import os
  import sys
  from datetime import datetime
  from invoke import task
label_desc: Use image node_id 16 for calling a global function with example usage: doc(ctx) without return types