public ShardingSphereSchema getSchema(final String schemaName) {
        return schemas.get(schemaName);
    }
@Test
    void assertGetSchema() {
        DatabaseType databaseType = mock(DatabaseType.class);
        RuleMetaData ruleMetaData = mock(RuleMetaData.class);
        ShardingSphereSchema schema = mock(ShardingSphereSchema.class);
        ShardingSphereDatabase database = new ShardingSphereDatabase("foo_db", databaseType, mock(ResourceMetaData.class), ruleMetaData, Collections.singletonMap("schema1", schema));
        assertThat(database.getSchema("schema1"), is(schema));
        assertNull(database.getSchema("non_existent_schema"));
    }