NSASCIIStringEncoding in parameters function in NSMutableURLRequest+Parameters.m causing crash when contains unicode data?

[AKPHYO]

Put any Unicode string in OAMutableURLRequest httpbody data,the library will crash in this function call.
NSArray *parameters = [self parameters] in the following code.

• (NSString *)_signatureBaseString {
  // OAuth Spec, Section 9.1.1 "Normalize Request Parameters"
  // build a sorted array of both request parameters and OAuth header parameters
  NSDictionary *tokenParameters = [token parameters];
  // 6 being the number of OAuth params in the Signature Base String
  NSArray *parameters = [self parameters];

I checked and found NSASCIIStringEncoding is being used in two places in the following functions in this file NSMutableURLRequest+Parameters.m

• (NSArray *)parameters {
  ...
• (void)setHTTPBodyWithString:(NSString *)body {
  ...

. I think they should be NSUTF8StringEncoding. I changed and tested. no crash anymore.