function visitSummary( node ) {
		switch ( node.type ) {
		case 'type':
			out.type = node.value;
			out.header += node.value;
			break;
		case 'scope':
			out.scope = node.value;
			out.header += '(' + node.value + ')';
			break;
		case 'breaking-change':
			out.header += '!';
			break;
		case 'text':
			out.subject = node.value;
			out.header += ': ' + node.value;
			break;
		default:
			break;
		}
	}
Processes a summary node and extracts relevant information.

@private
@param {Object} node - AST node