code: def get_schema_prefix(schema: RecordSchema, add_split=True):
      prefix_list = list()
      for spot_label in sorted(schema.type_list):
          prefix_list += [spot_prompt, spot_label]
      for asoc_label in sorted(schema.role_list):
          prefix_list += [asoc_prompt, asoc_label]
      prefix = " ".join(prefix_list)
      if add_split:
          return prefix + f" {text_start} "
      else:
          return prefix
  
file_path: DeepKE/src/deepke/name_entity_re/cross/extraction/dataset_processer.py
imports: from ..extraction.record_schema import RecordSchema
  from ..extraction.constants import spot_prompt, asoc_prompt, text_start
label_desc: Use image node_id 4 for calling the PrefixGenerator obj's underlying member method code with example usage: obj.get_schema_prefix(schema, add_split) and returns: unknown, prefix