def METHOD_NAME(mocker):
    find_price = mocker.patch('freqtrade.rpc.fiat_convert.CryptoToFiatConverter._find_price',
                              return_value=28000.0)
    fiat_convert = CryptoToFiatConverter()
    with pytest.raises(ValueError, match=r'The fiat us dollar is not supported.'):
        fiat_convert.get_price(crypto_symbol='btc', fiat_symbol='US Dollar')
    # Check the value return by the method
    pair_len = len(fiat_convert._pair_price)
    assert pair_len == 0
    assert fiat_convert.get_price(crypto_symbol='btc', fiat_symbol='usd') == 28000.0
    assert fiat_convert._pair_price['btc/usd'] == 28000.0
    assert len(fiat_convert._pair_price) == 1
    assert find_price.call_count == 1
    # Verify the cached is used
    fiat_convert._pair_price['btc/usd'] = 9867.543
    assert fiat_convert.get_price(crypto_symbol='btc', fiat_symbol='usd') == 9867.543
    assert find_price.call_count == 1