code: func (c *Context) Error(err error) *Error {
  	if err == nil {
  		panic("err is nil")
  	}
  
  	parsedError, ok := err.(*Error)
  	if !ok {
  		parsedError = &Error{
  			Err:  err,
  			Type: ErrorTypePrivate,
  		}
  	}
  
  	c.Errors = append(c.Errors, parsedError)
  	return parsedError
  }
docs: /************************************/
  /********* ERROR MANAGEMENT *********/
  /************************************/
  // Error attaches an error to the current context. The error is pushed to a list of errors.
  // It's a good idea to call Error for each error that occurred during the resolution of a request.
  // A middleware can be used to collect all the errors and push them to a database together,
  // print a log, or append it in the HTTP response.
  // Error will panic if err is nil.