public function get_grade( $post_id, $student, $use_cache = true ) {

		$post    = llms_get_post( $post_id );
		$student = llms_get_student( $student );

		$grade = $use_cache ? $this->get_grade_from_cache( $post, $student ) : false;

		// Grade not found in cache or we're not using the cache.
		if ( false === $grade ) {

			$grade = $this->calculate_grade( $post, $student );

			// Store in the cache.
			wp_cache_set(
				sprintf( '%d_grade', $post->get( 'id' ) ),
				$grade,
				sprintf( 'student_%d', $student->get( 'id' ) )
			);

		}

		return apply_filters( 'llms_get_grade', $grade, $post, $student );

	}