import unittest

class TestGetWaiters(unittest.TestCase):
    def setUp(self):
        # Mock data for testing
        self.waiters = [
            {'name': 'John', 'total_earnings': 100},
            {'name': 'Alice', 'total_earnings': 200},
            {'name': 'Bob', 'total_earnings': 150},
            {'name': 'Eve', 'total_earnings': 300}
        ]
        self.test_object = YourClass(self.waiters)  # Replace YourClass with your actual class name

    def test_no_filter(self):
        # Test when no filter is applied
        result = self.test_object.get_waiters()
        self.assertEqual(len(result), 4)  # Expecting all 4 waiters

    def test_min_earnings_filter(self):
        # Test when only min_earnings filter is applied
        result = self.test_object.get_waiters(min_earnings=150)
        self.assertEqual(len(result), 3)  # Expecting 3 waiters with earnings >= 150

    def test_max_earnings_filter(self):
        # Test when only max_earnings filter is applied
        result = self.test_object.get_waiters(max_earnings=200)
        self.assertEqual(len(result), 3)  # Expecting 3 waiters with earnings <= 200

    def test_both_filters(self):
        # Test when both min_earnings and max_earnings filters are applied
        result = self.test_object.get_waiters(min_earnings=150, max_earnings=250)
        self.assertEqual(len(result), 2)  # Expecting 2 waiters with earnings between 150 and 250

    def test_invalid_filters(self):
        # Test when invalid filters are provided
        result = self.test_object.get_waiters(min_earnings=500, max_earnings=1000)
        self.assertEqual(len(result), 0)  # Expecting no waiters as earnings range is invalid

if __name__ == '__main__':
    unittest.main()