in maven-plugin-testing-harness/src/main/java/org/apache/maven/api/plugin/testing/stubs/RepositorySystemSupplier.java [312:318]
public final ChecksumPolicyProvider getChecksumPolicyProvider() {
checkClosed();
if (checksumPolicyProvider == null) {
checksumPolicyProvider = createChecksumPolicyProvider();
}
return checksumPolicyProvider;
}