# Shorthand private method for GET request with URL parameters
sub _api_get($self, $uri_tail, $query_params) {
  my $uri= URI->new($self->base_uri . '/' . $uri_tail);
  $uri->query_form(%$query_params) if $query_params;
  my $req= HTTP::Request->new(GET => $uri, []);
  my $res= $self->_user_agent_request($req);
  return $self->_return_data_or_die_informatively($res, $req);
}

# Shorthand private method for POST request with JSON packet of parameters
sub _api_post($self, $uri_tail, $query_params, $body_data) {
  my $uri= URI->new($self->base_uri . '/' . $uri_tail);
  $uri->query_form(%$query_params) if $query_params;
  my $req= HTTP::Request->new(POST => $uri,
    [Content_Type => 'application/json'],
    encode_json($body_data)
  );
  my $res= $self->_user_agent_request($req);
  return $self->_return_data_or_die_informatively($res, $req);
}