### Question:
Environment { public boolean hasVariable(String name) { return !StringUtils.isEmpty(getString(name)); } Environment();  Environment(EnvironmentVariablesAccessor environmentVariablesAccessor); Map<String, String> getAllVariables(); Long getLong(String name); String getString(String name); Integer getInteger(String name); Boolean getBoolean(String name); Long getLong(String name, Long defaultValue); String getString(String name, String defaultValue); Integer getInteger(String name, Integer defaultValue); Boolean getBoolean(String name, Boolean defaultValue); Integer getPositiveInteger(String name, Integer defaultValue); Integer getNegativeInteger(String name, Integer defaultValue); T getVariable(String name, Function<String, T> mappingFunction); T getVariable(String name, Function<String, T> mappingFunction, T defaultValue); boolean hasVariable(String name);  }### Answer:
@Test void testHasVariable() { Mockito.when(environmentVariablesAccessor.getVariable("ab")) .thenReturn("0"); assertTrue(environment.hasVariable("ab")); }
@Test void testHasVariableWhenVariableIsMissing() { assertFalse(environment.hasVariable("ab")); }