code: def read_umls_definitions(meta_path: str, concept_details: Dict):
      """
      Read the types file MRDEF.RRF from a UMLS release and store it in
      concept_details dictionary. This function adds the `definition` field
      to the information of each concept
  
      MRDEF.RRF file format: a pipe-separated values
      Useful columns: CUI, SAB, SUPPRESS, DEF
  
      Args:
          meta_path: path to the META directory of an UMLS release
          concept_details: a dictionary to be filled with concept informations
      """
      definitions_filename = "MRDEF.RRF"
      headers = read_umls_file_headers(meta_path, definitions_filename)
      with open(
          f"{meta_path}/{definitions_filename}", encoding="utf-8"
      ) as fin:
          headers = read_umls_file_headers(
              meta_path, definitions_filename
          )
          for line in fin:
              splits = line.strip().split("|")
              assert len(headers) == len(splits)
              definition = dict(zip(headers, splits))
  
              if definition["SUPPRESS"] != "N":
                  continue
              is_from_preferred_source = (
                  definition["SAB"] in DEF_SOURCES_PREFERRED
              )
              concept = concept_details.get(definition["CUI"])
              if (
                  concept is None
              ):  # a small number of definitions are for concepts that don't exist
                  continue
  
              if (
                  "definition" not in concept
                  or is_from_preferred_source
                  and concept["is_from_preferred_source"] == "N"
              ):
                  concept["definition"] = definition["DEF"]
                  concept["is_from_preferred_source"] = (
                      "Y" if is_from_preferred_source else "N"
                  )
  
imports: from typing import Optional, List, Dict
  from scispacy.linking_utils import Entity, UmlsKnowledgeBase
label_desc: Use image node_id 4 for calling a global function with example usage: read_umls_definitions(meta_path, concept_details) without return types