Is it disable `is_theme` ? PhpCodeSniffer for WordPress coding Standard

FileNameSniff.php

/*
 * Generic check for lowercase hyphenated file names.
 */
if ( $fileName !== $expected && ( false === $this->is_theme || 1 !== preg_match( self::THEME_EXCEPTIONS_REGEX, $fileName ) ) ) {
  $this->phpcsFile->addError(
    'Filenames should be all lowercase with hyphens as word separators. Expected %s, but found %s.',
    0,
    'NotHyphenatedLowercase',
    array( $expected, $fileName )
  );
}
unset( $expected );