code: func (th TagHeader) ReadFlags() Flags {
  	flags := Flags{}
  	flags.Unsynchronisation = (th[5] & (1 << 0)) != 0     // 3.1.a
  	flags.ExtendedHeader = (th[5] & (1 << 1)) != 0        // 3.1.b
  	flags.ExperimentalIndicator = (th[5] & (1 << 2)) != 0 // 3.1.c
  	flags.FooterPresent = (th[5] & (1 << 3)) != 0         // 3.1.d
  
  	return flags
  }
docs: // ReadFlags reads the header flags