Return the flags that were supplied to the most recent successful call to the prepare method of this regular‐expression object. The behavior is undefined unless isPrepared() == true. Note that the returned value will be the bit‐wise inclusive‐or of 0 or more of the following values: ` k_FLAG_CASELESS k_FLAG_DOTMATCHESALL k_FLAG_MULTILINE k_FLAG_UTF8 k_FLAG_JIT k_FLAG_DUPNAMES ` Also note that k_FLAG_JIT is ignored, but still returned by this method, if isJitAvailable() is false.