def METHOD_NAME(self):
    """
    Return the list of prime numbers ``p`` for which the database of
    Conway polynomials contains polynomials over ``GF(p)``.
    EXAMPLES::
        sage: c = ConwayPolynomials()
        sage: P = c.primes()
        sage: 2 in P
        True
        sage: next_prime(10^7) in P
        False
    """
    return self._store.keys()