presto-main/src/main/java/io/prestosql/sql/analyzer/ExpressionAnalyzer.java/ExpressionAnalyzer/visitIdentifier
class ExpressionAnalyzer:        @Override
        protected Type visitIdentifier(Identifier node, StackableAstVisitorContext<Context> context)
        {
            ResolvedField resolvedField = context.getContext().getScope().resolveField(node, QualifiedName.of(node.getValue()));
            return handleResolvedField(node, resolvedField, context);
        }