code: func (f *FlagSet) Float64(name string, value float64, usage string) *float64 {
  	p := new(float64)
  	f.Float64Var(p, name, value, usage)
  	return p
  }
docs: // Float64 defines a float64 flag with specified name, default value, and usage string.
  // The return value is the address of a float64 variable that stores the value of the flag.