Does
Helper class with properties and methods that supply
            a number of constraints used in Asserts.
            
                
Returns a constraint that succeeds if the value
            is a file or directory and it exists.
            
Returns a ConstraintExpression that negates any
            following constraint.
            
protected Does()
Returns a new  SomeItemsConstraint checking for the
            presence of a particular object in the collection.
            
Returns a new  SomeItemsConstraint checking for the
            presence of a particular object in the collection.
            
Returns a new  ContainsConstraint. This constraint
            will, in turn, make use of the appropriate second-level
            constraint, depending on the type of the actual argument.
            This overload is only used if the item sought is a string,
            since any other type implies that we are looking for a
            collection member.
            
Returns a new DictionaryContainsKeyConstraint checking for the
            presence of a particular key in the Dictionary key collection.
            
Returns a new DictionaryContainsValueConstraint checking for the
            presence of a particular value in the Dictionary value collection.
            
Returns a constraint that succeeds if the actual
            value ends with the substring supplied as an argument.
            
Returns a constraint that succeeds if the actual
            value matches the regular expression supplied as an argument.
            
Returns a constraint that succeeds if the actual
            value matches the regular expression supplied as an argument.
            
Returns a constraint that succeeds if the actual
            value starts with the substring supplied as an argument.