message: changed errors
diff: use commands::{Command, CommandExecutor};
  use std::error;
  use std::sync::Arc;
  +use errors::anoncreds::AnoncredsError;
  pub struct AnoncredsAPI {
  command_executor: Arc<CommandExecutor>,
  @@ -11,17 +12,17 @@ impl AnoncredsAPI {
  AnoncredsAPI { command_executor: command_executor }
  }
  - pub fn create_master_secret(cb: Box<Fn(Result<(String), Box<error::Error>>) + Send>) {
  + pub fn create_master_secret(cb: Box<Fn(Result<(String), AnoncredsError>) + Send>) {
  }
  pub fn create_keys(schema: String,
  - cb: Box<Fn(Result<((String, String)), Box<error::Error>>) + Send>) {
  + cb: Box<Fn(Result<((String, String)), AnoncredsError>) + Send>) {
  }
  pub fn create_context_attribute(i_a: String, user_id: String,
  - cb: Box<Fn(Result<(String), Box<error::Error>>) + Send>) {
  + cb: Box<Fn(Result<(String), AnoncredsError>) + Send>) {
  }
  @@ -29,7 +30,7 @@ impl AnoncredsAPI {
  public_key_revocation: String,
  cb: Box<Fn(
  Result<((String, String, String, String)),
  - Box<error::Error>>
  + AnoncredsError>
  ) + Send>) {
  }
  @@ -39,20 +40,20 @@ impl AnoncredsAPI {
  secret_key: String, public_key_revocation: String,
  secret_key_revocation: String, tails: String,
  secret_key_accumulator: String,
  - cb: Box<Fn(Result<(String, String), Box<error::Error>>) + Send>) {
  + cb: Box<Fn(Result<(String, String), AnoncredsError>) + Send>) {
  }
  pub fn create_claim_request(master_secret: String, public_key: String,
  public_key_revocation: String, request_non_revocation: String,
  - cb: Box<Fn(Result<(String), Box<error::Error>>) + Send>) {
  + cb: Box<Fn(Result<(String), AnoncredsError>) + Send>) {
  }
  pub fn create_proof(proof_input: String, nonce: String, claims: String,
  public_key_revocation: String, accum: String, public_key: String,
  master_secret: String,
  - cb: Box<Fn(Result<(String, String), Box<error::Error>>) + Send>) {
  + cb: Box<Fn(Result<(String, String), AnoncredsError>) + Send>) {
  }
  @@ -60,7 +61,7 @@ impl AnoncredsAPI {
  nonce: String, public_key_revocation: String,
  public_key_accumulator: String, accumulator: String,
  public_key: String, attributes: String,
  - cb: Box<Fn(Result<(String), Box<error::Error>>) + Send>) {
  + cb: Box<Fn(Result<(String), AnoncredsError>) + Send>) {
  }
  }
  