Package check result: NOTE

Check: CRAN incoming feasibility, Result: NOTE
  Maintainer: ‘Alexander Ilich <ailich@usf.edu>’
  
  Found the following (possibly) invalid URLs:
    URL: https://prism.ucalgary.ca/bitstream/handle/1880/51900/texture%20tutorial%20v%203_0%20180206.pdf
      From: DESCRIPTION
            inst/doc/README.html
            README.md
      Status: Error
      Message: SSL peer certificate or SSH remote key was not OK [prism.ucalgary.ca]: server verification failed: certificate signer not trusted. (CAfile: /etc/ssl/certs/ca-certificates.crt CRLfile: none)

Changes to worse in reverse depends:

Package: ForestTools
Check: tests
New result: ERROR
    Running ‘testthat.R’ [13s/13s]
  Running the tests in ‘tests/testthat.R’ failed.
  Complete output:
    > # This file is part of the standard setup for testthat.
    > # It is recommended that you do not modify it.
    > #
    > # Where should you do additional test configuration?
    > # Learn more about the roles of various files in:
    > # * https://r-pkgs.org/testing-design.html#sec-tests-files-overview
    > # * https://testthat.r-lib.org/articles/special-files.html
    > 
    > library(testthat)
    > library(ForestTools)
    > 
    > test_check("ForestTools")
    [ FAIL 1 | WARN 0 | SKIP 0 | PASS 58 ]
    
    ══ Failed tests ════════════════════════════════════════════════════════════════
    ── Failure ('test_glcm_internal.R:115:3'): Edge cases: all zeroes ──────────────
    all(GLCMTextures::glcm_metrics(zero_glcm) %in% list(NaN, 1, 0)) is not TRUE
    
    `actual`:   FALSE
    `expected`: TRUE 
    
    [ FAIL 1 | WARN 0 | SKIP 0 | PASS 58 ]
    Error: Test failures
    Execution halted