private boolean authorizeNamespace(Set<NamespacePermission> permissions, String namespace,
    Permission.Action action) {
    if (permissions == null) {
      return false;
    }
    for (NamespacePermission permission : permissions) {
      if (permission.implies(namespace, action)) {
        return true;
      }
    }
    return false;
  }
Check if user has given action privilige in namespace scope.
@param user      user name
@param namespace namespace
@param action    one of action in [Read, Write, Create, Exec, Admin]
@return true if user has, false otherwise
hbase-server/src/main/java/org/apache/hadoop/hbase/security/access/AuthManager.java