text: from sqlalchemy import String, Column, ForeignKey
  
  COLOR_COLUMN_TYPE = String(7)
  PROJECT_ID_COLUMN_TYPE = String(5)
  PROJECT_ID_COLUMN_REFERENCE = Column(
      "project_id",
      PROJECT_ID_COLUMN_TYPE,
      ForeignKey("projects.project_id", ondelete="RESTRICT"),
      index=True,
      nullable=False,
  )
  ID_COLUMN_TYPE = String(15)
  PARENT_ID_COLUMN_REFERENCE = Column(
      "parent_id",
      ID_COLUMN_TYPE,
      index=True,
      nullable=False,
  )
  OBJECT_ID_COLUMN_REFERENCE = Column(
      "object_id",
      ID_COLUMN_TYPE,
      primary_key=True,
      nullable=False,
  )
  