gistfile1.php

<?php

class JsonDecoder implements DecoderInterface {

	public function decode( $data )
	{
		$decoded = @json_decode( $data, true );

		$decoded = $this->removeBooleans( $decoded );

		return $decoded;
	}

	private function removeBooleans( $array )
	{
		foreach ( $array as $key => $item ) {
			if ( is_array( $item ) ) {
				$array[ $key ] = $this->removeBooleans( $item );
			} else if ( $item === false ) {
				unset( $array[ $key ] );
			}
		}

		return $array;
	}
}