System.NullReferenceException
Object reference not set to an instance of an object.
   at MongoDB.Driver.Linq.Linq3Implementation.SerializerFinders.SerializerMap.AddSerializer(Expression node, IBsonSerializer serializer)
   at MongoDB.Driver.Linq.Linq3Implementation.SerializerFinders.SerializerFinderVisitor.AddNodeSerializer(Expression node, IBsonSerializer serializer)
   at MongoDB.Driver.Linq.Linq3Implementation.SerializerFinders.SerializerFinderVisitor.<VisitMethodCall>g__DeduceContainsKeyMethodSerializers|40_27(<>c__DisplayClass40_0&)
   at MongoDB.Driver.Linq.Linq3Implementation.SerializerFinders.SerializerFinderVisitor.<VisitMethodCall>g__DeduceMethodCallSerializers|40_0(<>c__DisplayClass40_0&)
   at MongoDB.Driver.Linq.Linq3Implementation.SerializerFinders.SerializerFinderVisitor.VisitMethodCall(MethodCallExpression node)
   at MongoDB.Driver.Linq.Linq3Implementation.SerializerFinders.SerializerFinderVisitor.Visit(Expression node)
   at System.Linq.Expressions.ExpressionVisitor.VisitLambda[T](Expression`1 node)
   at MongoDB.Driver.Linq.Linq3Implementation.SerializerFinders.SerializerFinderVisitor.VisitLambda[T](Expression`1 node)
   at MongoDB.Driver.Linq.Linq3Implementation.SerializerFinders.SerializerFinderVisitor.Visit(Expression node)
   at System.Linq.Expressions.ExpressionVisitor.VisitUnary(UnaryExpression node)
   at MongoDB.Driver.Linq.Linq3Implementation.SerializerFinders.SerializerFinderVisitor.VisitUnary(UnaryExpression node)
   at MongoDB.Driver.Linq.Linq3Implementation.SerializerFinders.SerializerFinderVisitor.Visit(Expression node)
   at System.Dynamic.Utils.ExpressionVisitorUtils.VisitArguments(ExpressionVisitor visitor, IArgumentProvider nodes)
   at System.Linq.Expressions.ExpressionVisitor.VisitMethodCall(MethodCallExpression node)
   at MongoDB.Driver.Linq.Linq3Implementation.SerializerFinders.SerializerFinderVisitor.VisitMethodCall(MethodCallExpression node)
   at MongoDB.Driver.Linq.Linq3Implementation.SerializerFinders.SerializerFinderVisitor.Visit(Expression node)
   at System.Dynamic.Utils.ExpressionVisitorUtils.VisitArguments(ExpressionVisitor visitor, IArgumentProvider nodes)
   at System.Linq.Expressions.ExpressionVisitor.VisitMethodCall(MethodCallExpression node)
   at MongoDB.Driver.Linq.Linq3Implementation.SerializerFinders.SerializerFinderVisitor.VisitMethodCall(MethodCallExpression node)
   at MongoDB.Driver.Linq.Linq3Implementation.SerializerFinders.SerializerFinderVisitor.Visit(Expression node)
   at MongoDB.Driver.Linq.Linq3Implementation.SerializerFinders.SerializerFinder.FindSerializers(Expression expression, ExpressionTranslationOptions translationOptions, SerializerMap nodeSerializers)
   at MongoDB.Driver.Linq.Linq3Implementation.Translators.TranslationContext.Create(Expression expression, Expression initialNode, IBsonSerializer initialSerializer, ExpressionTranslationOptions translationOptions, TranslationContextData data)
   at MongoDB.Driver.Linq.Linq3Implementation.Translators.TranslationContext.Create(Expression expression, IMongoQueryProviderInternal provider, ExpressionTranslationOptions translationOptions, TranslationContextData data)
   at MongoDB.Driver.Linq.Linq3Implementation.Translators.ExpressionToExecutableQueryTranslators.ExpressionToExecutableQueryTranslator.Translate[TDocument,TOutput](MongoQueryProvider`1 provider, Expression expression, ExpressionTranslationOptions translationOptions)
   at MongoDB.Driver.Linq.Linq3Implementation.MongoQuery`2.Execute()
   at MongoDB.Driver.Linq.Linq3Implementation.MongoQuery`2.GetEnumerator()
   at MongoDB.EntityFrameworkCore.Query.QueryingEnumerable`2.Enumerator.MoveNextHelper() in /Users/arthur.vickers/code/mongo-efcore-provider/src/MongoDB.EntityFrameworkCore/Query/QueryingEnumerable.cs:line 168
   at MongoDB.EntityFrameworkCore.Query.QueryingEnumerable`2.Enumerator.MoveNext() in /Users/arthur.vickers/code/mongo-efcore-provider/src/MongoDB.EntityFrameworkCore/Query/QueryingEnumerable.cs:line 110
   at System.Linq.Enumerable.<ToArray>g__EnumerableToArray|324_0[TSource](IEnumerable`1 source)
   at MongoDB.EntityFrameworkCore.FunctionalTests.Query.WhereDictionaryTests.Where_IDictionary_contains_key() in /Users/arthur.vickers/code/mongo-efcore-provider/tests/MongoDB.EntityFrameworkCore.FunctionalTests/Query/WhereDictionaryTests.cs:line 209
   at System.Reflection.MethodBaseInvoker.InterpretedInvoke_Method(Object obj, IntPtr* args)
   at System.Reflection.MethodBaseInvoker.InvokeWithNoArgs(Object obj, BindingFlags invokeAttr)