code: func (c *Context) FormFile(name string) (*multipart.FileHeader, error) {
  	if c.Request.MultipartForm == nil {
  		if err := c.Request.ParseMultipartForm(c.engine.MaxMultipartMemory); err != nil {
  			return nil, err
  		}
  	}
  	_, fh, err := c.Request.FormFile(name)
  	return fh, err
  }
docs: // FormFile returns the first file for the provided form key.