function removeDuplicateTokens( tokens ) {
	var out = [];
	var i;

	out.push( tokens[ 0 ] );
	for ( i = 1; i < tokens.length; i++ ) {
		if ( tokens[ i - 1 ].start !== tokens[ i ].start ) {
			out.push( tokens[ i ] );
		}
	}
	return out;
}
Removes duplicate tokens from a sorted tokens array.

@private
@param {Array<Object>} tokens - sorted tokens array
@returns {Array<Object>} array with unique tokens