code: protected final String getDefault(final String placeholderWithDefault) {
          int separatorIdx = placeholderWithDefault.indexOf(defaultSeparator);
          if (separatorIdx == -1) {
              return null;
          } else {
              return placeholderWithDefault.substring(separatorIdx + 1);
          }
      }
docs: extract the default value from the complete placeholder (the part between separator and suffix).
  
  @param placeholderWithDefault
  
  @return the default value, or null if none is given.
  
  @see #setPlaceholderPrefix
  @see #setDefaultSeparator
  @see #setPlaceholderSuffix