### Question:
GraphDomain { public int getSize() { return rateGraph.size(); } GraphDomain(); void addEdge(VertexDomain from, VertexDomain to, BigDecimal weight); int getSize(); BigDecimal searchCurrency(String currencyFrom, String currencyTo);  }### Answer:
@Test public void graphIsEmpty() throws Exception { assertEquals(0, mGraphDomain.getSize()); }