anchor.diff:  
       newRow
   
  -let private convertMapExpr (map: Map<string, Find>) =
  +let private convertMapToDict (map: Map<string, Find>) =
       Map.map (fun _ (value: Find) -> value.ToFindExpression()) map
       |> Map.toSeq
       |> dict
  
positive.code:     client.ExistsAsync(id, Option.toObj rev)
      |> Async.AwaitTask
  
  /// Checks that a document matching the given selector exists.
  let existsByMap (m: Map<string, obj>) props =
      let client = toClient props
  
      client.ExistsBySelector m
      |> Async.AwaitTask
  
  /// Checks that a document matching the given selector exists.
  /// Usage: existsByExpr<DocType> (<@ fun (c: DocType) -> c.SomeProp = SomeValue @>)
  /// NOTE: Davenport currently only supports simple 1 argument selectors.
  let existsByExpr<'doctype> (selector: Expr<('doctype -> bool)>) props =
      let client = toClient props
      let expr = toLinq selector
  
      client.ExistsBySelector expr
      |> Async.AwaitTask
  
  /// Checks that a document matching the given selector exists.
  let existsByMapExpr<'doctype> map props =
      let client = toClient props
      let selector = convertMapExpr map
  
      client.ExistsBySelector selector
      |> Async.AwaitTask
negative.code:     client.CountAsync()
      |> Async.AwaitTask
  
  let private countByDictionary selector props =
      let client = toClient props
  
      client.CountBySelectorAsync selector
      |> Async.AwaitTask
  
  /// Retrieves a count of all documents matching the given selector.
  let countBySelector = convertMapToDict >> countByDictionary
  
  /// Retrieves a count of all documents matching the given selector.
  /// Usage: countByExpr<DocType> (<@ fun (c: DocType) -> c.SomeProp = SomeValue @>)
  /// NOTE: Davenport currently only supports simple 1 argument selectors.
  let countByExpr<'doctype> = convertExprToMap<'doctype> >> countByDictionary
  
  /// Checks whether a document with the given id exists. If a revision is given, it will check whether that specific version exists.
  let exists id (rev: string option) props =
  