feature-envy-move-method-before.java

public class Phone {
    private final String unformattedNumber;
    public Phone(String unformattedNumber) {
        this.unformattedNumber = unformattedNumber;
    }
    public String getAreaCode() {
        return unformattedNumber.substring(0,3);
    }
    public String getPrefix() {
        return unformattedNumber.substring(3,6);
    }
    public String getNumber() {
        return unformattedNumber.substring(6,10);
    }
}

public class Customer {    
    private Phone mobilePhone;
    public String getMobilePhoneNumber() {
        return "(" + 
            mobilePhone.getAreaCode() + ") " +
            mobilePhone.getPrefix() + "-" +
            mobilePhone.getNumber();
    }
}