code: def check_paths(self, paths, update=None):
          ''' Check if the path is in the os environ, and if not add it
  
          Paramters:
              paths (OrderedDict):
                  An ordered dict containing all of the paths from the
                  a given section, as key:val = name:path
              update (bool):
                  If True, overwrites existing tree environment variables in your
                  local environment.  Default is False.
          '''
  
          # set up the exclusion list
          exclude = [] if not self.exclude else self.exclude \
              if isinstance(self.exclude, list) else [self.exclude]
  
          # check the path names
          for pathname, path in paths.items():
              if update and pathname.upper() not in exclude:
                  os.environ[pathname.upper()] = os.path.normpath(path)
              elif pathname.upper() not in os.environ:
                  os.environ[pathname.upper()] = os.path.normpath(pathf check_paths(self, paths, update=None):
          ''' Check if the path is in the os environ, and if not add it
  
          Paramters:
              paths (OrderedDict):
                  An ordered dict containing all of the paths from the
                  a given section, as key:val = name:path
              update (bool):
                  If True, overwrites existing tree environment variables in your
                  local environment.  Default is False.
          '''
  
          # set up the exclusion list
          exclude = [] if not self.exclude else self.exclude \
              if isinstance(self.exclude, list) else [self.exclude]
  
          # check the path names
          for pathname, path in paths.items():
              if update and pathname.upper() not in exclude:
                  os.environ[pathname.upper()] = os.path.normpath(path)
              elif pathname.upper() not in os.environ:
                  os.environ[pathname.upper()] = os.path.normpath(path)
docs: Check if the path is in the os environ, and if not add it
  
          Paramters:
              paths (OrderedDict):
                  An ordered dict containing all of the paths from the
                  a given section, as key:val = name:path
              update (bool):
                  If True, overwrites existing tree environment variables in your
                  local environment.  Default is False.