code: def grmat_gen(argv):
      vertices, edges, source_col, dest_col = grmat_wrapper.grmat_gen(
          argv
      )
  
      return vertices, edges, source_col, dest_col
  
label_desc: Use image node_id 1 for calling a global function with example usage: grmat_gen(argv) and returns: vertices,  edges,  source_col,  dest_col