You are an expert in writing code in many different languages. Your goal is to perform code completion for the following code, keeping in mind the rest of the code and the file meta data.
    Metadata details:
    filename: util.rs
    path of file: ./repos/h2/src/frame
    
    the code of the file until where you have to start completion: use std::fmt;

use super::Error;
use bytes::Bytes;

/// Strip padding from the given payload.
///
/// It is assumed that the frame had the padded flag set. This means that the
/// first byte is the len
    
    pub(super) fn flag_if(&mut self, enabled: bool, name: &str) -> &mut Self {
        if enabled {
            self.result = self.result.and_then(|()| {
                let prefix = if self.started {
                    " | "
                } else {
                    self.started = true;
                    ": "
                };

                write!(self.fmt, "{}{}", prefix, name)
            });
        }
        self
    }