public CompareToBuilder append(char lhs, char rhs) {
        if (comparison != 0) {
            return this;
        }
        comparison = ((lhs < rhs) ? -1 : ((lhs > rhs) ? 1 : 0));
        return this;
    }
Appends to the <code>builder</code> the comparison of
two <code>char</code>s.

@param lhs  left-hand value
@param rhs  right-hand value
@return this - used to chain append calls
android/android_framework/base/src/main/java/lang3/builder/CompareToBuilder.java