code: public void setNumericCollation(boolean flag) {
          checkNotFrozen();
          // sort substrings of digits as numbers
          if(flag == getNumericCollation()) { return; }
          CollationSettings ownedSettings = getOwnedSettings();
          ownedSettings.setFlag(CollationSettings.NUMERIC, flag);
          setFastLatinOptions(ownedSettings);
      }
docs: <strong>[icu]</strong> When numeric collation is turned on, this Collator makes
  substrings of digits sort according to their numeric values.
  
  <p>This is a way to get '100' to sort AFTER '2'. Note that the longest
  digit substring that can be treated as a single unit is
  254 digits (not counting leading zeros). If a digit substring is
  longer than that, the digits beyond the limit will be treated as a
  separate digit substring.
  
  <p>A "digit" in this sense is a code point with General_Category=Nd,
  which does not include circled numbers, roman numerals, etc.
  Only a contiguous digit substring is considered, that is,
  non-negative integers without separators.
  There is no support for plus/minus signs, decimals, exponents, etc.
  
  @param flag
  true to turn numeric collation on and false to turn it off
  @see #getNumericCollation
  @see #setNumericCollationDefault