presto-main/src/main/java/io/prestosql/sql/analyzer/ExpressionAnalyzer.java/Visitor/addOrReplaceExpressionCoercion
class Visitor:        private void addOrReplaceExpressionCoercion(Expression expression, Type type, Type superType)
        {
            NodeRef<Expression> ref = NodeRef.of(expression);
            expressionCoercions.put(ref, superType);
            if (typeCoercion.isTypeOnlyCoercion(type, superType)) {
                typeOnlyCoercions.add(ref);
            }
            else if (typeOnlyCoercions.contains(ref)) {
                typeOnlyCoercions.remove(ref);
            }
        }