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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def get_args(get_item):
 """Parse env, key, default out of input dict. Args: get_item: dict. contains keys env/key/default Returns: (env, key, has_default, default) tuple, where env: str. env var name. key: str. save env value to this context key. has_default: bool. True if default specified. default: the value of default, if specified. Raises: ContextError: envGet is not a list of dicts. KeyNotInContextError: If env or key not found in get_config. """

    if not isinstance(get_item, dict):
        raise ContextError('envGet must contain a list of dicts.')

    env = get_item.get('env', None)

    if not env:
        raise KeyNotInContextError(
            'context envGet[env] must exist in context for envGet.')

    key = get_item.get('key', None)

    if not key:
        raise KeyNotInContextError(
            'context envGet[key] must exist in context for envGet.')

    if 'default' in get_item:
        has_default = True
        default = get_item['default']
    else:
        has_default = False
        default = None

    return (env, key, has_default, default)