func New(callback func(cmd string, args ...string) (string, error)) (*TestRunner, error) {
	return &TestRunner{
		callback: callback,
	}, nil
}
// New builds a TestRunner to mock out command execution.
New builds a TestRunner to mock out command execution.
// New builds a TestRunner to mock out command execution .
func New(callback func(cmd string, args ...string) (string, error)) (*TestRunner, error) {
	return &TestRunner{
		callback: callback,
	}, nil
}
func New ( callback func ( cmd string , args ... string ) ( string , error ) ) ( * TestRunner , error ) { return & TestRunner { callback : callback , } , nil }
New builds a TestRunner to mock out command execution.
New builds a TestRunner to mock out command execution .