code: public void setLowerCaseFirst(boolean lowerfirst) {
          checkNotFrozen();
          if (lowerfirst == isLowerCaseFirst()) { return; }
          CollationSettings ownedSettings = getOwnedSettings();
          ownedSettings.setCaseFirst(lowerfirst ? CollationSettings.CASE_FIRST : 0);
          setFastLatinOptions(ownedSettings);
      }
docs: Sets the orders of lower cased characters to sort before upper cased characters, in strength TERTIARY. The
  default mode is false. If true is set, the RuleBasedCollator will sort lower cased characters before the upper
  cased ones. Otherwise, if false is set, the RuleBasedCollator will ignore case preferences.
  
  @param lowerfirst
  true for sorting lower cased characters before upper cased characters, false to ignore case
  preferences.
  @see #isLowerCaseFirst
  @see #isUpperCaseFirst
  @see #setUpperCaseFirst
  @see #setCaseFirstDefault