Update the copy independently afterwards and check that
the original remains intact (that is, no dangling
references point to objects in the copied environment).
+ Copy the original with some construction variable
+ updates and check that the original remains intact
+ and the copy has the updated values.
env1 = Environment(XXX = 'x', YYY = 'y')
+ env3 = env1.Copy(XXX = 'x3', ZZZ = 'z3')
+ assert env3.Dictionary['XXX'] == 'x3'
+ assert env3.Dictionary['YYY'] == 'y'
+ assert env3.Dictionary['ZZZ'] == 'z3'
+ assert env1 == env1copy
"""Test the simple ability to retrieve known construction
variables from the Dictionary and check for well-known