serializer

Currently we save every URI ever qname'd forever in here: https://github.com/RDFLib/rdflib/blob/master/rdflib/namespace.py#L289

If you serialize a big graph in a store that is off disk, we may run out of memory.

Either:

• Add a lru_cache (from py3 functools + this 2.7 implementation
• Depend on

I've recently come to realize that the 'one-size-fits-all' mega-snippets on marzer.github.io/tomlplusplus aren't necessarily useful for everyone, and I should break them up into smaller sub-examples. I'd be totally happy to accept help with this, though that may be wishful thinking!

We want to implement a custom method with payload key name as metricValues, but the proper ruby method name should be snake_case.

class MetricPeriodSerializer < Panko::Serializer
        attributes :period, :metricValues

        def metricValues
           [{
            'name' => 'metric1',	
            'value' => object.metric_1	
          },	
           {