def output_value_to_column_value(v)
      if v.kind_of?(Array)
        if v.length == 0
          nil
        elsif v.length == 1
          v.first
        elsif v.first.kind_of?(String)
          v.join(@internal_delimiter)
        else
          # Not a string? Um, raise for now?
          raise ArgumentError.new("Traject::SequelWriter, multiple non-String values provided: #{v}")
        end
      else
        v
      end
    end
def output_value_to_column_value(v)
      if v.kind_of?(Array)
        if v.length == 0
          nil
        elsif v.length == 1
          v.first
        elsif v.first.kind_of?(String)
          v.join(@internal_delimiter)
        else
          # Not a string? Um, raise for now?
          raise ArgumentError.new("Traject::SequelWriter, multiple non-String values provided: #{v}")
        end
      else
        v
      end
    end
Traject context.output_hash values are arrays.
 turn them into good column values, joining strings if needed.

 Single values also accepted, even though not traject standard, they
 will be passed through unchanged.