historical parameter order of implode($pieces, $glue) used

from php.net:

string implode ( string $glue , array $pieces )

implode() can, for historical reasons, accept its parameters in either order. For consistency with explode(), however, it may be less confusing to use the documented order of arguments.

There are at the moment 7 usages in the library where the order is ($pieces, $glue) instead of ($glue, $pieces):

/Mail/src/transports/imap/imap_transport.php
2 times:
$ids = implode( $messages, ',' );

Graph/src/options/svg_driver.php
5 times:
implode( $values, ', ' )