allOf function
This returns a matcher that matches if all of the matchers passed as arguments (up to 7) match.
Instead of passing the matchers separately they can be passed as a single List argument. Any argument that is not a matcher is implicitly wrapped in a Matcher to check for equality.
Implementation
Matcher allOf(arg0, [arg1, arg2, arg3, arg4, arg5, arg6]) {
return new _AllOf(_wrapArgs(arg0, arg1, arg2, arg3, arg4, arg5, arg6));
}