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##### SUMMARY
<!--- Explain the problem briefly below -->
Ansible documents a fact_caching_prefix option for the jsonfile cache plugin. It does not appear to do anything. Also, the fact_caching_connection option is documented as `_uri` rather than `_connection`.

##### ISSUE TYPE
- Bug Report

##### COMPONENT NAME
<!--- Write the short name of the module, plugin, task or feature below, use your best guess if unsure -->
jsonfile

##### ANSIBLE VERSION
<!--- Paste verbatim output from "ansible --version" between quotes -->
```paste below
ansible 2.9.8
  config file = /home/mark/src/ansible/ansible2/ansible.cfg
  configured module search path = [u'/home/mark/.ansible/plugins/modules', u'/usr/share/ansible/plugins/modules']
  ansible python module location = /home/mark/src/ansible-playground/venv-2.9/local/lib/python2.7/site-packages/ansible
  executable location = /home/mark/src/ansible-playground/venv-2.9/bin/ansible
  python version = 2.7.12 (default, Oct  8 2019, 14:14:10) [GCC 5.4.0 20160609]
```

##### CONFIGURATION
<!--- Paste verbatim output from "ansible-config dump --only-changed" between quotes -->
```paste below

```

##### OS / ENVIRONMENT
<!--- Provide all relevant information below, e.g. target OS versions, network device firmware, etc. -->
Ubuntu

##### STEPS TO REPRODUCE
<!--- Describe exactly how to reproduce the problem, using a minimal test-case -->

<!--- Paste example playbooks or commands between quotes below -->
```yaml

```

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##### EXPECTED RESULTS
<!--- Describe what you expected to happen when running the steps above -->


##### ACTUAL RESULTS
<!--- Describe what actually happened. If possible run with extra verbosity (-vvvv) -->

<!--- Paste verbatim command output between quotes -->
```paste below

```

ret = dict()
        for key in self.keys():
            ret[key] = self.get(key)
        return ret
    @abstractmethod
    def _load(self, filepath):
        """
        Read data from a filepath and return it as a value
        :arg filepath: The filepath to read from.
        :returns: The value stored in the filepath
        This method reads from the file on disk and takes care of any parsing
        and transformation of the data before returning it.  The value
        returned should be what Ansible would expect if it were uncached data.
        .. note:: Filehandles have advantages but calling code doesn't know
            whether this file is text or binary, should be decoded, or accessed via
            a library function.  Therefore the API uses a filepath and opens
            the file inside of the method.
        """
        pass
    @abstractmethod
    def _dump(self, value, filepath):
        """
        Write data to a filepath
        :arg value: The value to store
        :arg filepath: The filepath to store it at
        """
        pass
class CachePluginAdjudicator(MutableMapping):