def list_grants(Limit=None, Marker=None, KeyId=None):
    """
    List the grants for a specified key.
    See also: AWS API Documentation
    
    Examples
    The following example lists grants for the specified CMK.
    Expected Output:
    
    :example: response = client.list_grants(
        Limit=123,
        Marker='string',
        KeyId='string'
    )
    
    
    :type Limit: integer
    :param Limit: Use this parameter to specify the maximum number of items to return. When this value is present, AWS KMS does not return more than the specified number of items, but it might return fewer.
            This value is optional. If you include a value, it must be between 1 and 100, inclusive. If you do not include a value, it defaults to 50.
            

    :type Marker: string
    :param Marker: Use this parameter in a subsequent request after you receive a response with truncated results. Set it to the value of NextMarker from the truncated response you just received.

    :type KeyId: string
    :param KeyId: [REQUIRED]
            A unique identifier for the customer master key. This value can be a globally unique identifier or the fully specified ARN to a key.
            Key ARN Example - arn:aws:kms:us-east-1:123456789012:key/12345678-1234-1234-1234-123456789012
            Globally Unique Key ID Example - 12345678-1234-1234-1234-123456789012
            

    :rtype: dict
    :return: {
        'Grants': [
            {
                'KeyId': 'string',
                'GrantId': 'string',
                'Name': 'string',
                'CreationDate': datetime(2015, 1, 1),
                'GranteePrincipal': 'string',
                'RetiringPrincipal': 'string',
                'IssuingAccount': 'string',
                'Operations': [
                    'Decrypt'|'Encrypt'|'GenerateDataKey'|'GenerateDataKeyWithoutPlaintext'|'ReEncryptFrom'|'ReEncryptTo'|'CreateGrant'|'RetireGrant'|'DescribeKey',
                ],
                'Constraints': {
                    'EncryptionContextSubset': {
                        'string': 'string'
                    },
                    'EncryptionContextEquals': {
                        'string': 'string'
                    }
                }
            },
        ],
        'NextMarker': 'string',
        'Truncated': True|False
    }
    
    
    :returns: 
    (string) --
    
    """
    pass
