old_contents: 
  from flask_appbuilder.models.mixins import AuditMixin, BaseMixin, FileColumn, ImageColumn
  from sqlalchemy import Table, Column, Integer, String, Boolean, ForeignKey
  from flask_appbuilder import Base
  from flask_appbuilder.security.models import User
  from app import db
  """
  
  You can use the extra Flask-AppBuilder fields and Mixin's
  
  AuditMixin will add automatic timestamp of created and modified by who
  
  
  """
          
  class Project(AuditMixin, db.Model):
      id = db.Column(db.Integer, primary_key=True)
      name =  db.Column(db.String(150), unique = True, nullable=False)
      
  class ProjectFiles(db.Model):
      id = db.Column(db.Integer, primary_key=True)
      project_id = db.Column(db.Integer, db.ForeignKey('project.id'))
      project = db.relationship("Project")
      file = db.Column(FileColumn, nullable=False)
      
  
new_contents: from flask_appbuilder.models.mixins import AuditMixin, BaseMixin, FileColumn, ImageColumn
  from sqlalchemy import Table, Column, Integer, String, Boolean, ForeignKey
  from sqlalchemy.orm import relationship
  from flask_appbuilder import Base
  from flask_appbuilder.security.models import User
  from flask_appbuilde import Base
  
  """
  
  You can use the extra Flask-AppBuilder fields and Mixin's
  
  AuditMixin will add automatic timestamp of created and modified by who
  
  
  """
  
  class Project(AuditMixin, Base):
      id = Column(Integer, primary_key=True)
      name =  Column(String(150), unique = True, nullable=False)
      
  class ProjectFiles(Base):
      id = Column(Integer, primary_key=True)
      project_id = Column(Integer, ForeignKey('project.id'))
      project = relationship("Project")
      file = Column(FileColumn, nullable=False)
      
  
subject: Update models.py