PipelineDefinitionBuilderLookupTInput, TIntermediate, TForeignDocument, TAsElement, TAs, TOutput Method (PipelineDefinitionTInput, TIntermediate, IMongoCollectionTForeignDocument, BsonDocument, PipelineDefinitionTForeignDocument, TAsElement, ExpressionFuncTOutput, TAs, AggregateLookupOptionsTForeignDocument, TOutput)

public static PipelineDefinition<TInput, TOutput> Lookup<TInput, TIntermediate, TForeignDocument, TAsElement, TAs, TOutput>(
	this PipelineDefinition<TInput, TIntermediate> pipeline,
	IMongoCollection<TForeignDocument> foreignCollection,
	BsonDocument let,
	PipelineDefinition<TForeignDocument, TAsElement> lookupPipeline,
	Expression<Func<TOutput, TAs>> as,
	AggregateLookupOptions<TForeignDocument, TOutput> options = null
)
where TAs : Object, IEnumerable<TAsElement>

<ExtensionAttribute>
Public Shared Function Lookup(Of TInput, TIntermediate, TForeignDocument, TAsElement, TAs As {Object, IEnumerable(Of TAsElement)}, TOutput) ( 
	pipeline As PipelineDefinition(Of TInput, TIntermediate),
	foreignCollection As IMongoCollection(Of TForeignDocument),
	let As BsonDocument,
	lookupPipeline As PipelineDefinition(Of TForeignDocument, TAsElement),
	as As Expression(Of Func(Of TOutput, TAs)),
	Optional options As AggregateLookupOptions(Of TForeignDocument, TOutput) = Nothing
) As PipelineDefinition(Of TInput, TOutput)

[<ExtensionAttribute>]
static member Lookup : 
        pipeline : PipelineDefinition<'TInput, 'TIntermediate> * 
        foreignCollection : IMongoCollection<'TForeignDocument> * 
        let : BsonDocument * 
        lookupPipeline : PipelineDefinition<'TForeignDocument, 'TAsElement> * 
        as : Expression<Func<'TOutput, 'TAs>> * 
        ?options : AggregateLookupOptions<'TForeignDocument, 'TOutput> 
(* Defaults:
        let _options = defaultArg options null
*)
-> PipelineDefinition<'TInput, 'TOutput>  when 'TAs : Object and IEnumerable<'TAsElement>