code: public static void applyToText(CharSequence charSequence, Typeface typeface,
              int start, int end) {
          if (charSequence instanceof Spannable) {
              Spannable spannable = (Spannable) charSequence;
              spannable.setSpan(getInstance(typeface), start, end, Spanned.SPAN_INCLUSIVE_INCLUSIVE);
          }
      }
docs: This method does the same as {@link #applyToText(CharSequence, Typeface)}, but let you
  specify the start and end index where the span will be applied.
  
  @param charSequence a {@code CharSequence} implementing {@code Spannable} to apply the styles
  @param typeface     the {@code Typeface} that you want to be applied on the text
  @param start        the start index where to apply the span
  @param end          the end index where to apply the span
  @see Spannable#setSpan