Use context.hash instead of context.object_id for cache index, as object_id can be recycled due to garbage collection.

Author: gkellogg

lib/json/ld/context.rb

@@ -1789,7 +1789,7 @@ def bnode(value = nil)
     # @return [Hash{String => Hash{String => String}}]
     # @todo May want to include @set along with container to allow selecting terms using @set over those without @set. May require adding some notion of value cardinality to compact_iri
     def inverse_context
-      Context.inverse_cache[self.object_id] ||= begin
+      Context.inverse_cache[self.hash] ||= begin
         result = {}
         default_language = (self.default_language || '@none').downcase
         term_definitions.keys.sort do |a, b|