presto-main/src/main/java/io/prestosql/sql/planner/Coercer.java/Coercer/rewriteExpression
class Coercer:        @Override
        public Expression rewriteExpression(Expression expression, Void context, ExpressionTreeRewriter<Void> treeRewriter)
        {
            Type target = coercions.get(NodeRef.of(expression));

            Expression rewritten = treeRewriter.defaultRewrite(expression, null);
            if (target != null) {
                rewritten = new Cast(
                        rewritten,
                        toSqlType(target),
                        false,
                        typeOnlyCoercions.contains(NodeRef.of(expression)));
            }

            return rewritten;
        }