code: def get_foreign_key_declaration_sql(self, foreign_key):
          
          sql = self.get_foreign_key_base_declaration_sql(foreign_key)
          sql += self.get_advanced_foreign_key_options_sql(foreign_key)
  
          return sql
docs: Obtain DBMS specific SQL code portion needed to set the FOREIGN KEY constraint
          of a field declaration to be used in statements like CREATE TABLE.
  
          :param foreign_key: The foreign key
          :type foreign_key: ForeignKeyConstraint
  
          :rtype: str