code: public Object getCurrentValue(Change change) {
          try {
              for (PropertyDescriptor descriptor : PropertyUtils.getInstance().getDescriptors(change.getClass())) {
                  if (descriptor.getDisplayName().equals(this.parameterName)) {
                      Method readMethod = descriptor.getReadMethod();
                      if (readMethod == null) {
                          readMethod = change.getClass().getMethod(
                              "is" + StringUtil.upperCaseFirst(descriptor.getName())
                          );
                      }
                      return readMethod.invoke(change);
                  }
              }
              throw new RuntimeException("Could not find readMethod for " + this.parameterName);
          } catch (Exception e) {
              throw new UnexpectedLiquibaseException(e);
          }
      }
docs: Returns the current value of this parameter for the given Change.