// Prefilters
// 1) They are useful to introduce custom dataTypes (see transport/jsonp for an example)
// 2) These are called:
// * BEFORE asking for a transport
// * AFTER param serialization (s.data is a string if s.processData is true)
// Prefilters
// 1) They are useful to introduce custom dataTypes (see transport/jsonp for an example)
// 2) These are called:
// * BEFORE asking for a transport
// * AFTER param serialization (s.data is a string if s.processData is true)