class_docstr: Class describing basic methods that package should provide
  
  Parameters
  ----------
  `key`: str
      Name this package should be queried for
  `versions`: str or PckgVer class object
      List of versions this package is available for
  `name`: str, optional, default = None
      Name of this package used during installation. If empty it is the same as the key
class_docstr_tok: ["Class","describing","basic","methods","that","package","should","provide","Parameters","--","--","--","--","--","`","key","`",":","str","Name","this","package","should","be","queried","for","`","versions","`",":","str","or","PckgVer","class","object","List","of","versions","this","package","is","available","for","`","name","`",":","str",",","optional",",","default","=","None","Name","of","this","package","used","during","installation",".","If","empty","it","is","the","same","as","the","key"]
docstr: Retrieves only compatible versions of this package from provided `versions` list
  
  Parameters
  ----------
  `versions`: list
      List of versions to be checked. All versions that evaluate to True are returned
docstr_tok: ["Retrieves","only","compatible","versions","of","this","package","from","provided","`","versions","`","list","Parameters","--","--","--","--","--","`","versions","`",":","list","List","of","versions","to","be","checked",".","All","versions","that","evaluate","to","True","are","returned"]
code: def filter_versions(self, versions):
      """Retrieves only compatible versions of this package from provided `versions` list
  
      Parameters
      ----------
      `versions`: list
          List of versions to be checked. All versions that evaluate to True are returned
      """
      # no need to convert PckgVer to string, it is done by get_install_string when printed
      return [v for v in versions if v]
  
imports: import argparse
  import sys
  from pip._vendor.packaging.version import parse
  import urllib.parse
  from urllib.request import urlopen, HTTPError, Request, URLError
label_desc: Use image node_id 7 for calling the BasePackage obj's underlying member method code with example usage: obj.filter_versions(versions) and returns: unknown