How to use the xblock.fields.Boolean function in XBlock

def __init__(self, help=None, default=UNSET, scope=Scope.content, display_name=None, **kwargs):  # pylint: disable=redefined-builtin
        super(Boolean, self).__init__(help, default, scope, display_name,
                                      values=({'display_name': "True", "value": True},
                                              {'display_name': "False", "value": False}),
                                      **kwargs)

default='',
        scope=Scope.content,
        display_name=_('Enabled transcripts'),
        help=_(
            'Add transcripts in different languages. Click below to specify a language and upload an .srt transcript'
            ' file for that language.'
        )
    )

    transcripts_enabled = Boolean(
        default=False,
        scope=Scope.preferences,
        help="Transcripts are enabled or not"
    )

    captions_enabled = Boolean(
        default=False,
        scope=Scope.preferences,
        help="Captions are enabled or not"
    )

    player_state_fields = (
        'current_time', 'muted', 'playback_rate', 'volume', 'transcripts_enabled',
        'captions_enabled', 'captions_language', 'transcripts'
    )

    @property
    def course_default_language(self):
        """
        Utility method returns course's language.

        Falls back to 'en' if runtime doen't provide `modulestore` service.

help='Seconds played back after the start'
    )

    playback_rate = Float(
        default=1,
        scope=Scope.preferences,
        help='Supported video playbacks speeds are: 0.5, 1, 1.5, 2'
    )

    volume = Float(
        default=1,
        scope=Scope.preferences,
        help='Video volume: from 0 to 1'
    )

    muted = Boolean(
        default=False,
        scope=Scope.preferences,
        help="Video is muted or not"
    )

    captions_language = String(
        default='',
        scope=Scope.preferences,
        help="ISO code for the current language for captions and transcripts"
    )

    transcripts = String(
        default='',
        scope=Scope.content,
        display_name=_('Enabled transcripts'),
        help=_(

cell_timeout = Integer(
        help="Max seconds to wait for each cell to execute",
        scope=Scope.settings,
        display_name="Cell Timeout (s)",
        default=15
    )

    max_file_size = Integer(
        help="Max allowable file size of student uploaded file (Bytes)",
        scope=Scope.settings,
        display_name="Max File Size (B)",
        default=None
    )

    allow_network = Boolean (
        help="If True, allows network access from student notebook",
        scope=Scope.settings,
        display_name="Network Allowed",
        default=False
    )

    allow_graded_dl = Boolean (
        help="If True, allows student to download .html version of their autograded notebook",
        scope=Scope.settings,
        display_name="Allow Graded NB Download",
        default=False
    )

    # ------- Internal Fields -------
    nb_name = String(
        help="filename of the notebook",

"""
        contentstore_service = self.runtime.service(self, 'contentstore')
        if contentstore_service:
            return contentstore_service.StaticContent

        return import_from('xmodule.contentstore.content', 'StaticContent')


class TranscriptsMixin(XBlock):
    """
    TranscriptsMixin class to encapsulate transcripts-related logic.
    """

    THREE_PLAY_MEDIA_API_DOMAIN = 'https://static.3playmedia.com/'

    threeplaymedia_streaming = Boolean(
        default=False,
        display_name=_('Direct 3PlayMedia'),
        scope=Scope.content,
        help=_("Direct <a href="http://www.3playmedia.com/">3PlayMedia</a> transcripts usage enabled.")
    )

    threeplaymedia_apikey = String(
        default='',
        display_name=_('3PlayMedia API Key'),
        help=_('You can generate a client token following official documentation of your video platform\'s API.'),
        scope=Scope.content,
        resettable_editor=False
    )

    threeplaymedia_file_id = String(
        default='',

import string  # pylint: disable=W0402
import time

from xblock.core import XBlock
from xblock.fields import Integer, Scope, String, Any, Boolean, Dict
from xblock.run_script import run_script
from xblock.fragment import Fragment


class ProblemBlock(XBlock):
    """A generalized container of InputBlocks and Checkers.

    """
    script = String(help="Python code to compute values", scope=Scope.content, default="")
    seed = Integer(help="Random seed for this student", scope=Scope.user_state, default=0)
    problem_attempted = Boolean(help="Has the student attempted this problem?", scope=Scope.user_state, default=False)
    has_children = True

    @classmethod
    def parse_xml(cls, node, runtime, keys):
        block = runtime.construct_xblock_from_class(cls, keys)

        # Find 

display_name = String(
        default=_('Video'),
        display_name=_('Component Display Name'),
        help=_('The name students see. This name appears in the course ribbon and as a header for the video.'),
        scope=Scope.content,
    )

    href = String(
        default='',
        display_name=_('Video URL'),
        help=_('URL of the video page. E.g. https://example.wistia.com/medias/12345abcde'),
        scope=Scope.content
    )

    download_video_allowed = Boolean(
        default=False,
        scope=Scope.content,
        display_name=_('Video Download Allowed'),
        help=_(
            "Allow students to download this video if they cannot use the edX video player."
            " A link to download the file appears below the video."
        ),
        resettable_editor=False
    )

    download_video_url = String(
        default='',
        display_name=_('Video file URL'),
        help=_("The URL where you've posted non hosted versions of the video. URL must end in .mpeg, .mp4, .ogg, or"
               " .webm. (For browser compatibility, we strongly recommend .mp4 and .webm format.) To allow students to"
               " download these videos, set Video Download Allowed to True."),

icon_class = "video"

    '''
    Fields
    '''
    display_name = String(display_name="Display Name",
        default="Video JS",
        scope=Scope.settings,
        help="This name appears in the horizontal navigation at the top of the page.")

    url = String(display_name="Video URL",
        default="http://vjs.zencdn.net/v/oceans.mp4",
        scope=Scope.content,
        help="The URL for your video.")
    
    allow_download = Boolean(display_name="Video Download Allowed",
        default=True,
        scope=Scope.content,
        help="Allow students to download this video.")
    
    source_text = String(display_name="Source document button text",
        default="",
        scope=Scope.content,
        help="Add a download link for the source file of your video. Use it for example to provide the PowerPoint or PDF file used for this video.")
    
    source_url = String(display_name="Source document URL",
        default="",
        scope=Scope.content,
        help="Add a download link for the source file of your video. Use it for example to provide the PowerPoint or PDF file used for this video.")
    
    start_time = String(display_name="Start time",
        default="",

max_file_size = Integer(
        help="Max allowable file size of student uploaded file (Bytes)",
        scope=Scope.settings,
        display_name="Max File Size (B)",
        default=None
    )

    allow_network = Boolean (
        help="If True, allows network access from student notebook",
        scope=Scope.settings,
        display_name="Network Allowed",
        default=False
    )

    allow_graded_dl = Boolean (
        help="If True, allows student to download .html version of their autograded notebook",
        scope=Scope.settings,
        display_name="Allow Graded NB Download",
        default=False
    )

    # ------- Internal Fields -------
    nb_name = String(
        help="filename of the notebook",
        scope=Scope.settings,
        default=""
    )

    nb_upload_datetime = String(
        help="UTC datetime the notebook was uploaded",
        scope=Scope.settings,

help=_(
            "This value must match what is in the 'Content Protection' area of the Azure Media Services portal"
        ),
        default="urn:xblock-azure-media-services",
        scope=Scope.settings
    )
    captions = List(
        display_name=_("Captions"),
        help=_("A list of caption definitions"),
        scope=Scope.settings
    )
    caption_ids = List(
        default=[],
        scope=Scope.settings
    )
    transcripts_enabled = Boolean(
        display_name=_("Transcripts enabled"),
        help=_("Transcripts switch"),
        default=True,
        scope=Scope.settings
    )
    download_url = String(
        display_name=_("Video Download URL"),
        help=_("A download URL"),
        scope=Scope.settings
    )

    # These are what become visible in the Mixin editor
    editable_fields = (
        'display_name', 'video_url', 'verification_key', 'protection_type',
        'token_issuer', 'token_scope', 'captions', 'transcripts_enabled', 'download_url',
        'edx_video_id', 'caption_ids'