presto-main/src/main/java/io/prestosql/sql/analyzer/ExpressionAnalyzer.java/ExpressionAnalyzer/getExpressionType
class ExpressionAnalyzer:    private Type getExpressionType(Expression expression)
    {
        requireNonNull(expression, "expression cannot be null");

        Type type = expressionTypes.get(NodeRef.of(expression));
        checkState(type != null, "Expression not yet analyzed: %s", expression);
        return type;
    }