func (m *MockClient) Root() (Root, error) {
	a := m.Called()
	return a.Get(0).(Root), a.Error(1)
}
Root is a mocking a method
package horizon
import (
	"github.com/stretchr/testify/mock"
	"golang.org/x/net/context"
)
type MockClient struct {
	mock.Mock
}