@Override
    public MapEntryMappers createCopy() {
        return new MapEntryMappers(this);
    }
Sets the column that map entry values are loaded from. If set, values will be loaded from the given column, using the {@link ColumnMapper}
registered for the value type. If unset, values will be loaded using the {@link RowMapper} registered for the value type, from whichever columns
that row mapper uses.

@param valueColumn the value column name.
@return this config object, for call chaining
core/src/main/java/org/jdbi/v3/core/mapper/MapEntryMappers.java