Missing Aggregation Usageedit

a => a
.Missing("projects_without_a_description", m => m
    .Field(p => p.Description.Suffix("keyword"))
)
new MissingAggregation("projects_without_a_description")
{
    Field = Field<Project>(p => p.Description.Suffix("keyword"))
}

Example json output. 

{
  "projects_without_a_description": {
    "missing": {
      "field": "description.keyword"
    }
  }
}

Handling Responsesedit

response.ShouldBeValid();
var projectsWithoutDesc = response.Aggregations.Missing("projects_without_a_description");
projectsWithoutDesc.Should().NotBeNull();