docs: def load_orthologs(fo: IO, metadata: dict):
      """Load orthologs into ArangoDB
  
      Args:
          fo: file obj - orthologs file
          metadata: dict containing the metadata for orthologs
      """
  
      version = metadata["metadata"]["version"]
  
      # LOAD ORTHOLOGS INTO ArangoDB
      with timy.Timer("Load Orthologs") as timer:
          arango_client = arangodb.get_client()
          belns_db = arangodb.get_belns_handle(arango_client)
          arangodb.batch_load_docs(
              belns_db, orthologs_iterator(fo, version), on_duplicate="update"
          )
  
          log.info(
              "Load orthologs",
              elapsed=timer.elapsed,
              source=metadata["metadata"]["source"],
          )
  
          # Clean up old entries
          remove_old_ortholog_edges = f"""
              FOR edge in ortholog_edges
                  FILTER edge.source == "{metadata["metadata"]["source"]}"
                  FILTER edge.version != "{version}"
                  REMOVE edge IN ortholog_edges
          """
          remove_old_ortholog_nodes = f"""
              FOR node in ortholog_nodes
                  FILTER node.source == "{metadata["metadata"]["source"]}"
                  FILTER node.version != "{version}"
                  REMOVE node IN ortholog_nodes
          """
          arangodb.aql_query(belns_db, remove_old_ortholog_edges)
          arangodb.aql_query(belns_db, remove_old_ortholog_nodes)
  
      # Add metadata to resource metadata collection
      metadata["_key"] = f"Orthologs_{metadata['metadata']['source']}"
      try:
          belns_db.collection(arangodb.belns_metadata_name).insert(metadata)
      except ArangoError as ae:
          belns_db.collection(arangodb.belns_metadata_name).replace(metadata)