code: public void setField(String field, String value, boolean isUnescapable) {
          if (!isUnescapable) {
              otherSimpleFields.put(field, value);
          }
          else {
              otherUnescapableFields.put(field, value);
          }
      }
docs: Set generic, unescapable VCard field. If unescapable is set to true, XML maybe a part of the
  value.
  
  @param value         value of field
  @param field         field to set. See {@link #getField(String)}
  @param isUnescapable True if the value should not be escaped, and false if it should.