setCandidateEncodings  
  Sets the candidate encodings for the file loading.
The encodings are tried in the same order as the list.
For convenience, @candidate_encodings can contain duplicates. Only the first occurrence of a duplicated encoding is kept in the list.
By default the candidate encodings are (in that order in the list):
- If set, the class@File's encoding as returned by method@File.get_encoding. 
- The default candidates as returned by func@Encoding.get_default_candidates. 
Parameters
candidateEncodings 
a list of #GtkSourceEncodings.