code: public static <TItem> Bson min(final String fieldName, final TItem value) {
          return new SimpleUpdate<TItem>(fieldName, value, "$min");
      }
docs: Creates an update that sets the value of the field to the given value if the given value is less than the current value of the
  field.
  
  @param fieldName the non-null field name
  @param value     the value
  @param <TItem>   the value type
  @return the update
  @mongodb.driver.manual reference/operator/update/min/ $min