public CreateUserPoolRequest withUsernameAttributes(java.util.Collection<String> usernameAttributes) {
        setUsernameAttributes(usernameAttributes);
        return this;
    }
<p>
Specifies whether a user can use an email address or phone number as a username when they sign up.
</p>

@param usernameAttributes
       Specifies whether a user can use an email address or phone number as a username when they sign up.
@return Returns a reference to this object so that method calls can be chained together.
@see UsernameAttributeType
aws-java-sdk-cognitoidp/src/main/java/com/amazonaws/services/cognitoidp/model/CreateUserPoolRequest.java