text: from sqlathanor.declarative import BaseModel
  from sqlathanor.schema import relationship, Column
  
  class FlaskBaseModel(BaseModel):
      """Base class that establishes shared methods, attributes, and properties.
  
      Designed to be supplied as a ``model_class`` when initializing
      :doc:`Flask-SQLAlchemy <flask_sqlalchemy:index>`.
  
      .. seealso::
  
        For detailed explanation of functionality, please see
        :class:`BaseModel <sqlathanor.declarative.BaseModel>`.
  
      """
      pass
  
  def initialize_flask_sqlathanor(db):
      """Initialize **SQLAthanor** contents on a `Flask-SQLAlchemy`_ instance.
  
      :param db: The
        :class:`flask_sqlalchemy.SQLAlchemy <flask_sqlalchemy:flask_sqlalchemy.SQLAlchemy>`
        instance.
      :type db: :class:`flask_sqlalchemy.SQLAlchemy <flask_sqlalchemy:flask_sqlalchemy.SQLAlchemy>`
  
      :returns: A mutated instance of ``db`` that replaces `SQLAlchemy`_ components and
        their `Flask-SQLAlchemy`_ flavors with **SQLAthanor** analogs while maintaining
        `Flask-SQLAlchemy`_ and `SQLAlchemy`_ functionality and interfaces.
      :rtype: :class:`flask_sqlalchemy.SQLAlchemy <flask_sqlalchemy:flask_sqlalchemy.SQLAlchemy>`
  
      :raises ImportError: if called when `Flask-SQLAlchemy`_ is not installed
      :raises ValueError: if ``db`` is not an instance of
        :class:`flask_sqlalchemy.SQLAlchemy <flask_sqlalchemy:flask_sqlalchemy.SQLAlchemy>`
  
      """
      from flask_sqlalchemy import _wrap_with_default_query_class, SQLAlchemy
  
      if not isinstance(db, SQLAlchemy):
          raise ValueError('db must be an instance of flask_sqlalchemy.SQLAlchemy')
  
      db.Column = Column
      db.relationship = _wrap_with_default_query_class(relationship, db.Query)
  
      return db
  