In Python 3 __ne__ by default delegates to __eq__ and inverts the
result, but in Python 2 they urge you to define __ne__ when you
define __eq__ for it to work properly [1].There are no implied
relationships among the comparison operators. The truth of x==y
does not imply that x!=y is false. Accordingly, when defining
__eq__(), one should also define __ne__() so that the operators
will behave as expected.
[1]https://docs.python.org/2/reference/datamodel.html#object.__ne__
Also remove class SubStringMatcher becasue this class isn't used
following commit 7035639dfd239b52d4ed46aae50f78d16ec8cbfe.
Change-Id: Ia2131f72a79226b0c2f3662b84661eb870d1d692
de51a6db36