code: func (f *Fpdf) SetHeaderFuncMode(fnc func(), homeMode bool) {
  	f.headerFnc = fnc
  	f.headerHomeMode = homeMode
  }
docs: // SetHeaderFuncMode sets the function that lets the application render the
  // page header. See SetHeaderFunc() for more details. The value for homeMode
  // should be set to true to have the current position set to the left and top
  // margin after the header function is called.