code: def main():
      """
      A small demonstration of a tsurgeon operation
      """
      text = "( (SBARQ (WHNP (WP Who)) (SQ (VP (VBZ sits) (PP (IN in) (NP (DT this) (NN seat))))) (. ?)))"
      trees = tree_reader.read_trees(text)
  
      tregex = "WP=wp"
      tsurgeon = "relabel wp WWWPPP"
  
      result = process_trees(trees, (tregex, tsurgeon))
      print(result)
  
file_path: stanza/stanza/server/tsurgeon.py
imports: from stanza.models.constituency import tree_reader
  from stanza.models.constituency.parse_tree import Tree
  from stanza.protobuf import TsurgeonRequest, TsurgeonResponse
  from stanza.server.java_protobuf_requests import send_request, build_tree, from_tree, JavaProtobufContext
label_desc: Use image node_id 4 for calling a global function with example usage: main() without return types