Implement this by replacing the code passed into Builder
with the following:

"{countPlaceholder, plural, =0{message0} =1{message1} =2{message2} few{messageFew} many{messageMany} other{messageOther}}"

The expression above will be replaced by the message variation
(message0, message1, …) corresponding to the value
of the countPlaceholder. Only the messageOther field is required.

The following example defines a message that pluralizes the word, “wombat”:

Using a plural method is easy enough, just pass it the item count parameter:

Similar to plurals, you can also choose a value based on a String placeholder.
This is most often used to support gendered languages. The syntax is:

"{selectPlaceholder, select, case{message} ... other{messageOther}}"

The following example defines a message that selects a pronoun based on gender: