presto-spi/src/main/java/io/prestosql/spi/connector/ColumnMetadata.java/ColumnMetadata/toString
class ColumnMetadata:    @Override
    public String toString()
    {
        StringBuilder sb = new StringBuilder("ColumnMetadata{");
        sb.append("name='").append(name).append('\'');
        sb.append(", type=").append(type);
        sb.append(", ").append(nullable ? "nullable" : "nonnull");
        if (comment != null) {
            sb.append(", comment='").append(comment).append('\'');
        }
        if (extraInfo != null) {
            sb.append(", extraInfo='").append(extraInfo).append('\'');
        }
        if (hidden) {
            sb.append(", hidden");
        }
        if (!properties.isEmpty()) {
            sb.append(", properties=").append(properties);
        }
        sb.append('}');
        return sb.toString();
    }