anchor.diff:  
     /// Fill missing values only between the first and last non-missing values
     /// [category:Missing values]
  +  [<CompiledName("FillMissingInside")>]
     let fillMissingInside direction (series:Series<'K, 'T>) = 
       if not series.IsOrdered then invalidOp "Series must be sorted to use fillMissingInside"
       series.Observations |> Seq.tryFirstAndLast |> function
  
positive.code:   /// This operation is only supported on ordered series. The method throws
    /// `InvalidOperationException` when the series is not ordered.
    ///
    /// [category:Lookup, resampling and scaling]
    let resampleInto keys dir f (series:Series<'K, 'V>) =
      series.Resample(keys, dir, (fun k s -> f k s))
  
  
negative.code:   /// This operation is only supported on ordered series. The method throws
    /// `InvalidOperationException` when the series is not ordered. 
    ///
    /// [category:Sampling, resampling and advanced lookup]
    let resampleUniformInto (fillMode:Lookup) (keyProj:'K1 -> 'K2) (nextKey:'K2 -> 'K2) f (series:Series<'K1, 'V>) =
      let min, max = series.KeyRange
      
  