def stub_env_config(inst, hash = nil)
      (hash = inst; inst = nil) if inst.is_a?(Hash)
      inst = @env || env unless inst

      hash = Jekyll::Utils.deep_merge_hashes(inst.asset_config, hash)
      allow(inst).to receive(:asset_config).and_return(hash)
    end
def stub_env_config(inst, hash = nil)
      (hash = inst; inst = nil) if inst.is_a?(Hash)
      inst = @env || env unless inst

      hash = Jekyll::Utils.deep_merge_hashes(inst.asset_config, hash)
      allow(inst).to receive(:asset_config).and_return(hash)
    end
------------------------------------------------------------------------