by rhcarvalho:
Four occurrences:
func (*Int) MarshalText
MarshalText implements the encoding.TextMarshaler interface
func (*Int) UnmarshalText
UnmarshalText implements the encoding.TextUnmarshaler interface
func (*Rat) MarshalText
MarshalText implements the encoding.TextMarshaler interface
func (*Rat) UnmarshalText
UnmarshalText implements the encoding.TextUnmarshaler interface