text: import datetime
  
  from database.database_schemas import Schemas
  from database.dsstox.generic_substances import GenericSubstances
  from sqlalchemy import Column, Integer, String, DateTime, ForeignKey
  from sqlalchemy.orm import relationship
  
  from database.base import Base
  
  
  class Synonyms(Base):
      """Maps to synonyms table in dsstox databases."""
  
      __tablename__ = 'synonyms'
      __table_args__ = {'schema': Schemas.dsstox_schema}
  
      id = Column(Integer, primary_key=True, nullable=False)
      fk_generic_substance_id = Column(ForeignKey(GenericSubstances.id), nullable=False)
      identifier = Column(String(1024), nullable=False)
      synonym_quality = Column(String(255), nullable=False)
      synonym_type = Column(String(255))
      qc_notes = Column(String(1024))
      created_by = Column(String(255), nullable=False)
      updated_by = Column(String(255), nullable=False)
      created_at = Column(DateTime, default=datetime.datetime.now, nullable=False)
      updated_at = Column(DateTime, default=datetime.datetime.now, nullable=False)
      source = Column(String(255))
  
      generic_substance = relationship("GenericSubstances")
  