code: public static String format(final String messagePattern,
                                  final Object arg1,
                                  final Object arg2) {
          int i = 0;
          int len = messagePattern.length();
  
          StringBuffer sbuf = new StringBuffer(messagePattern.length() + 50);
  
          for (int l = 0; l < 2; l++) {
              int j = messagePattern.indexOf(DELIM_START, i);
  
              if (j == -1 || (j + 1 == len)) {
                  // no more variables
                  if (i == 0) { // this is a simple string
                      return messagePattern;
                  } else {
                      // add the tail string which contains no variables
                      // and return the result.
                      sbuf.append(messagePattern.substring(i,
                                      messagePattern.length()));
                      return sbuf.toString();
                  }
              } else {
                  char delimStop = messagePattern.charAt(j + 1);
                  if ((delimStop != DELIM_STOP)) {
                      // invalid DELIM_START/DELIM_STOP pair
                      sbuf.append(messagePattern.substring(i,
                              messagePattern.length()));
                      return sbuf.toString();
                  }
                  sbuf.append(messagePattern.substring(i, j));
                  if (l == 0) {
                      sbuf.append(arg1);
                  } else {
                      sbuf.append(arg2);
                  }
                  i = j + 2;
              }
          }
          // append the characters following the second {} pair.
          sbuf.append(messagePattern.substring(i, messagePattern.length()));
          return sbuf.toString();
      }
docs: /**
  Performs a two argument substitution for the 'messagePattern' passed as
  parameter.
  <p/>
  For example, <code>MessageFormatter.format("Hi {}. My name is {}.",
  "there", "David");</code> will return the string
  "Hi there. My name is David.".
  <p/>
  The '{}' pair is called a formatting element. It serves to designate the
  location where the arguments need to be inserted within
  the message pattern.
  
  @param messagePattern
  The message pattern which will be parsed and formatted
  @param arg1
  The first argument to replace the first formatting element
  @param arg2
  The second argument to replace the second formatting element
  @return The formatted message