public function test_build_value_compare_in() {
    $q = new WP_Date_Query( array() );

    // Single integer
    $found = $q->build_value( 'IN', 4 );
    $this->assertSame( '(4)', $found );

    // Single non-integer
    $found = $q->build_value( 'IN', 'foo' );
    $this->assertFalse( $found );

    // Array of integers
    $found = $q->build_value( 'IN', array( 1, 4, 7 ) );
    $this->assertSame( '(1,4,7)', $found );

    // Array containing non-integers
    $found = $q->build_value( 'IN', array( 1, 'foo', 7 ) );
    $this->assertSame( '(1,7)', $found );
  }