How to use the proclaim.isTrue function in proclaim

it('should return `true` if a matching binary is found', function () {
			assert.isTrue(passingResult);
		});

it('should callback with `true` if a matching binary is found', function () {
			assert.isTrue(passingResult);
		});

it('should call the expected control with the given element', function () {
            var el = createDomElement();
            var ctrl = {};
            cuff.controls.foo = sinon.stub().returns(ctrl);
            cuff.controls.bar = sinon.spy();
            cuff.bind(el, 'foo');
            assert.isTrue(cuff.controls.foo.withArgs(el).calledOnce);
            assert.isFalse(cuff.controls.bar.called);
        });

pa11y.sniff(opts, function () {
				assert.isTrue(reporter.begin.calledOnce, 'begin');
				assert.isTrue(reporter.log.called, 'log');
				assert.isTrue(reporter.handleResult.calledOnce, 'handleResult');
				assert.isTrue(reporter.end.calledOnce, 'end');
				done();
			});
		});

nextTick(function () {
                    assert.isTrue(callback.withArgs(undefined, 'bar').calledOnce);
                    done();
                });
            });