public UpdateDefinition<TDocument> Push<TItem>(
	Expression<Func<TDocument, IEnumerable<TItem>>> field,
	TItem value
)

Public Function Push(Of TItem) ( 
	field As Expression(Of Func(Of TDocument, IEnumerable(Of TItem))),
	value As TItem
) As UpdateDefinition(Of TDocument)

member Push : 
        field : Expression<Func<'TDocument, IEnumerable<'TItem>>> * 
        value : 'TItem -> UpdateDefinition<'TDocument>