code: func (a *Assertions) InEpsilon(expected interface{}, actual interface{}, epsilon float64, msgAndArgs ...interface{}) bool {
  	if h, ok := a.t.(tHelper); ok {
  		h.Helper()
  	}
  	return InEpsilon(a.t, expected, actual, epsilon, msgAndArgs...)
  }
docs: // InEpsilon asserts that expected and actual have a relative error less than epsilon