code: func (m *Meta) WasTouched(field string) bool {
  	m.detectTouchedFlags()
  	ptr, ok := m.fieldsMap()[field]
  	if !ok {
  		panic(fmt.Sprintf("no such meta field %s", field))
  	}
  	_, yes := m.touched[ptr]
  	return yes
  }
docs: // WasTouched returns true if the field (given by its Starlark snake_case name)
  // was explicitly set via CLI flags or via lucicfg.config(...) in Starlark.
  //
  // Panics if the field is unrecognized.