public CommandTester thenExpectStartsWith(String expected) {
        String actual = this.renderBuffer();
        assertTrue(actual.trim().startsWith(expected.trim()), "expected '" + actual + "' to start with '" + expected + "'");

        if (this.permissions != null) {
            assertEquals(this.checkedPermissions, this.permissions.keySet());
        }

        return this.clearMessageBuffer();
    }
Asserts that the current contents of the message buffer starts with the given input string.

@param expected the expected contents
@return this
standalone/src/test/java/me/lucko/luckperms/standalone/utils/CommandTester.java