How to return document field for NEST client with search?

I have following mappings:

{
  "mappings": {
      "properties" : {
        "CompletionTime" : {
          "type" : "date",
          "format": "date_hour_minute_second",
          "fields" : {
            "keyword" : {
              "type" : "date"
            }
          }
        },
        "Description" : {
          "type" : "text",
          "fields" : {
            "keyword" : {
              "type" : "keyword",
              "ignore_above" : 256
            }
          }
        },
        "InitiatorName" : {
          "type" : "text",
          "fields" : {
            "keyword" : {
              "type" : "keyword",
              "ignore_above" : 256
            }
          }
        },
        "StartTime" : {
          "type" : "date",
          "format": "date_hour_minute_second",
          "fields" : {
            "keyword" : {
              "type" : "date"
            }
          }
        },
        "TargetObjectName" : {
          "type" : "text",
          "fields" : {
            "keyword" : {
              "type" : "keyword",
              "ignore_above" : 256
            }
          }
        },
        "TargetObjectType" : {
          "type" : "text",
          "fields" : {
            "keyword" : {
              "type" : "keyword",
              "ignore_above" : 256
            }
          }
        }
      }
  }
}

I created following code for C# Nest client:

public DateTime GetNewestDocumentDate()
        {
            var searchResponse = this.ec.Client.Search<Record>(s => s
                    .Query(q => q.MatchAll())
                    .Sort(so => so
                        .Field(fs => fs
                            .Field("StartTime")
                            .Order(SortOrder.Descending)
                        ))
                    .Size(1)
            );
            var a = searchResponse.Documents;
            Console.WriteLine(JsonSerializer.Serialize(a));

            return a.StartTime;
        }

I am new with C# and Elastic so I don't know how to return document field. In my case it should be something like this, but my syntax is not correct. var a is an array and a[0].StartTime didn't pass check in Visual Studio.

Solution:

var a = searchResponse.Documents.ElementAt(0);
            
return a.StartTime;

Hi dreic! I'm glad you found the solution. Indeed, Documents is a collection of the hits, deserialised to your Record type so you can enumerate those and access any of the properties as required.