code: def _mysql_and_check_constraints_exist(self, config):
      # 1. we have mysql / mariadb and
      # 2. it enforces check constraints
      if exclusions.against(config, ["mysql", "mariadb"]):
          if sqla_compat._is_mariadb(config.db.dialect):
              mnvi = sqla_compat._mariadb_normalized_version_info
              norm_version_info = mnvi(config.db.dialect)
              return norm_version_info >= (10, 2)
          else:
              norm_version_info = config.db.dialect.server_version_info
              return norm_version_info >= (8, 0, 16)
      else:
          return False
  
imports: from sqlalchemy import exc
  from sqlalchemy import Index
  from sqlalchemy import text
  from alembic.testing import exclusions
  from alembic.testing.requirements import SuiteRequirements
  from alembic.util import compat
  from alembic.util import sqla_compat
label_desc: Use image node_id 45 for calling the DefaultRequirements obj's underlying member method code with example usage: obj._mysql_and_check_constraints_exist(config) and returns: False, unknown, unknown