I just wanted to try out min_children / max_children filter functionality of ES using a [HasChildFilterDescriptor](https://github.com/elastic/elasticsearch-net/blob/a139f054d3c6b669bbfcb758e12232f440bf04f8/src/Nest/DSL/Filter/HasChildFilterDescriptor.cs) and I noticed that, contrary to its [HasChildQueryDescriptor](https://github.com/elastic/elasticsearch-net/blob/4e44bfd575e023aea0a0693a0c9d4ea497363a42/src/Nest/DSL/Query/HasChildQueryDescriptor.cs) counterpart, the Filter does not have the Min/MaxChildren Properties, even though [ES seems to support these in Filters](https://www.elastic.co/guide/en/elasticsearch/reference/1.4/query-dsl-has-child-filter.html), too.