Add extrapolation methods to mass matrix tests

Description

This issue does not include a description.

Contributor guide

Tech stack

None

Domain

testing

Issue type

test

DifficultyEstimated implementation difficulty for a new contributor, from 1 for very small changes to 5 for expert-level work.

4

Estimated timeA rough time range for an experienced contributor to investigate, implement, test, and prepare a pull request.

1-2 days

Activity statusHow available the issue appears right now: fresh, active, stale, blocked, or waiting on maintainer input.

stale

ClarityHow clearly the issue explains the expected change, acceptance criteria, and next step.

mostly clear

Prerequisites

Familiarity with ODE solversKnowledge of mass matricesUnderstanding of extrapolation methods

Newbie friendlinessA 1-100 score estimating how approachable this issue is for first-time contributors.

20

Research direction

Examine the existing mass matrix tests in the repository's test directory (e.g., test/mass matrix.jl). Understand how extrapolation methods are implemented in the source code, likely in src/. Review other ODE solver packages for inspiration on test patterns. Consider asking maintainers for clarification on expected test coverage via a comment on the issue.