class_docstr: Base class for different types of credentials
  
  Note: While subclasses can define their own `_FIELDS`, they are actually
  assumed to have particular keys by the implementation of (some)
  authenticators. `HTTPRequestsAuthenticator` and its subclasses for example,
  assume `user` and `password` to be valid keys.
class_docstr_tok: ["Base","class","for","different","types","of","credentials","Note",":","While","subclasses","can","define","their","own","`","_FIELDS","`",",","they","are","actually","assumed","to","have","particular","keys","by","the","implementation","of","(","some",")","authenticators",".","`","HTTPRequestsAuthenticator","`","and","its","subclasses","for","example",",","assume","`","user","`","and","`","password","`","to","be","valid","keys","."]
docstr: Set field(s) of the credential
code: def set(self, **kwargs):
      """Set field(s) of the credential"""
      for f, v in kwargs.items():
          if f not in self._FIELDS:
              raise ValueError(
                  "Unknown field %s. Known are: %s"
                  % (f, self._FIELDS.keys())
              )
          self._keyring.set(self.name, f, v)
  
imports: import time
  from ..support.exceptions import AccessDeniedError, CapturedException
  from ..support.keyring_ import keyring
  from ..ui import ui
  from ..utils import auto_repr
  from ..support.network import iso8601_to_epoch
  from datalad import cfg
  from datalad.config import anything2bool
  from datalad.distribution.dataset import Dataset
  from datalad.local.gitcredential import GitCredentialInterface
  from logging import getLogger
label_desc: Use image node_id 10 for calling the Credential obj's underlying member method code with example usage: obj.set() without return types