class Environment

An Environment object is capable of setting up and tearing down an

environment. You should subclass this to define your own

environment(s).

An Environment object does the set-up and tear-down in virtual

methods SetUp() and TearDown() instead of the constructor and the

destructor, as:

1. You cannot safely throw from a destructor. This is a problem

as in some cases Google Test is used where exceptions are enabled, and

we may want to implement ASSERT_* using exceptions where they are

available.

2. You cannot use ASSERT_* directly in a constructor or

destructor.