input: [0] file [1] string [2] 
output: File from which to obtain response content. Response type is inferred from the file name extension for a few well-known media types (text, SMIL, GIF, JPEG, PNG, BMP/WBMP, WAV, AMR, MP3, etc.), otherwise it defaults to application/octet-stream. See below for further information on how fetched content is converted to an MM.