code: def dummy_schema() -> "DatabaseParametersSchemaMixin":
      """
      Fixture providing a dummy schema.
      """
      from superset.databases.schemas import (
          DatabaseParametersSchemaMixin,
      )
  
      class DummySchema(DatabaseParametersSchemaMixin, Schema):
          sqlalchemy_uri = fields.String()
  
      return DummySchema()
  
file_path: superset/tests/unit_tests/databases/schema_tests.py
imports: from typing import TYPE_CHECKING
  import pytest
  from marshmallow import fields, Schema, ValidationError
  from pytest_mock import MockFixture
label_desc: Use image node_id 1 for calling a global function with example usage: dummy_schema() and returns: DummySchema