Binary.InferContentType(source as binary) as record
Returns a record with field Content.Type that contains the inferred MIME-type. If the inferred content type is text/*, and an encoding code page is detected, then additionally returns field Content.Encoding that contains the encoding of the stream. If the inferred content type is text/csv, and the format is delimited, additionally returns field Csv.PotentialDelimiter containing a table for analysis of potential delimiters. If the inferred content type is text/csv, and the format is fixed-width, additionally returns field Csv.PotentialPositions containing a list for analysis of potential fixed width column positions.