code: private boolean hashesMatch(Dependency dependency1, Dependency dependency2) {
          if (dependency1 == null || dependency2 == null || dependency1.getSha1sum() == null || dependency2.getSha1sum() == null) {
              return false;
          }
          return dependency1.getSha1sum().equals(dependency2.getSha1sum());
      }
docs: Compares the SHA1 hashes of two dependencies to determine if they are
  equal.
  
  @param dependency1 a dependency object to compare
  @param dependency2 a dependency object to compare
  @return true if the sha1 hashes of the two dependencies match; otherwise
  false