code: protected static final String underbarStringToSentence(String str) {
          if (str == null) {
              return null;
          }
          char[] buf = new char[str.length()];
          // preserve case of first character
          buf[0] = str.charAt(0);
          for (int i = 1; i < str.length(); i++) {
              char c = str.charAt(i);
              if (c >= 'A' && c <= 'Z') {
                  c += 0x20;
              } else if (c == 0x5f) {
                  // convert underbar to space
                  c = 0x20;
              }
              buf[i] = c;
          }
          return new String(buf);
      }
docs: Turn "FOO_BAR_BAZ" into "Foo bar baz".