from django.db import models

class Author(models.Model):

    first_name = models.CharField(max_length=255)

    last_name = models.CharField(max_length=255)

    dob = models.DateField()

    def __init__(self, *args, **kwargs):

        super(Author, self).__init__(*args, **kwargs)

        # Protect against annotations being passed to __init__ --

        # this'll make the test suite get angry if annotations aren't

        # treated differently than fields.

        for k in kwargs:

            assert k in [f.attname for f in self._meta.fields], \

                "Author.__init__ got an unexpected paramater: %s" % k

class Book(models.Model):

    title = models.CharField(max_length=255)

    author = models.ForeignKey(Author)

    paperback = models.BooleanField()

    opening_line = models.TextField()

class Coffee(models.Model):

    brand = models.CharField(max_length=255, db_column="name")

class Reviewer(models.Model):

    reviewed = models.ManyToManyField(Book)

class FriendlyAuthor(Author):

    pass