count tests
===========

    >>> import re2
    >>> re2.set_fallback_notification(re2.FALLBACK_EXCEPTION)

This one is from http://docs.python.org/library/re.html?#finding-all-adverbs:

    >>> re2.count(r"\w+ly", "He was carefully disguised but captured quickly by police.")
    2

Groups should not affect count():

    >>> re2.count(r"(\w+)=(\d+)", "foo=1,foo=2")
    2
    >>> re2.count(r"(\w)\w", "fx")
    1

Zero matches:

    >>> re2.count("(f)", "gggg")
    0

A pattern matching an empty string:

    >>> re2.count(".*", "foo")
    2

    >>> re2.count("", "foo")
    4

contains tests
==============

	>>> re2.contains('a', 'bbabb')
	True
	>>> re2.contains('a', 'bbbbb')
	False

    >>> re2.set_fallback_notification(re2.FALLBACK_QUIETLY)
