Graph and Query APIs

def graph_create(%GraphCommons.Graph{} = graph) do
    if rdf_store_admin() do
      graph_delete()
      graph_update(graph)
    else
      {:error, rdf_store()}
    end
end
def graph_delete() do
  if rdf_store_admin() do
    {:ok, env} = Tesla.delete(rdf_store_admin())
    GraphCommons.Graph.new(env.body, "", :rdf)
    env
  else
    {:error, rdf_store()}
  end
end
def graph_read() do
  if rdf_store_admin() do
    {:ok, env} = Tesla.get(rdf_store_admin())
    GraphCommons.Graph.new(env.body, "", :rdf)
  else
    {:error, rdf_store()}
  end
end
def graph_update(%GraphCommons.Graph{} = graph) do
  if rdf_store_admin() do
    {:ok, env} = Tesla.post(rdf_store_admin(), graph.data, headers: [{"content-type", "text/turtle"}])
    GraphCommons.Graph.new(env.body, "", :rdf)
  else
    {:error, rdf_store()}
  end
end