code: def get_single_int_pk_colname(table_: Table) -> Optional[str]:
      
      n_pks = 0
      int_pk_names = []
      for col in table_.columns:
          if col.primary_key:
              n_pks += 1
              if is_sqlatype_integer(col.type):
                  int_pk_names.append(col.name)
      if n_pks == 1 and len(int_pk_names) == 1:
          return int_pk_names[0]
      return None
docs: If a table has a single-field (non-composite) integer PK, this will
      return its database column name; otherwise, None.
  
      Note that it is legitimate for a database table to have both a composite
      primary key and a separate ``IDENTITY`` (``AUTOINCREMENT``) integer field.
      This function won't find such columns.