+import org.opendaylight.yangtools.yang.parser.antlr.IfFeatureExpressionLexer;
+import org.opendaylight.yangtools.yang.parser.antlr.IfFeatureExpressionParser;
+import org.opendaylight.yangtools.yang.parser.antlr.IfFeatureExpressionParser.Identifier_ref_argContext;
+import org.opendaylight.yangtools.yang.parser.antlr.IfFeatureExpressionParser.If_feature_exprContext;
+import org.opendaylight.yangtools.yang.parser.antlr.IfFeatureExpressionParser.If_feature_factorContext;
+import org.opendaylight.yangtools.yang.parser.antlr.IfFeatureExpressionParser.If_feature_termContext;
+import org.opendaylight.yangtools.yang.parser.antlr.IfFeatureExpressionParserBaseVisitor;