code: public static Matcher<Result> exact(final String exact) {
          return new Matcher<Result>() {
              @Override
              public Result matches(String input, boolean isEof) {
                  return exact.equals(input)
                          ? success(input, "", input)
                          : failure(input, input.length() > exact.length());
              }
  
              @Override
              public String toString() {
                  return generateToString("exact", exact);
              }
          };
      }
docs: Creates a matcher that matches when the given string is equal to the
  input buffer contents.
  <p/>
  If the result is successful, the {@link net.sf.expectit.Result#getBefore()} returns an
  empty string, the {@link net.sf.expectit.Result#group()} returns the entire input buffer.
  
  @param exact the string to match.
  @return the result.