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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 codemirror_field_css_bundle(field):
 """ Filter to get CodeMirror CSS bundle name needed for a single field. Example: :: {% load djangocodemirror_tags %} {{ form.myfield|codemirror_field_css_bundle }} Arguments: field (djangocodemirror.fields.CodeMirrorField):
 A form field. Raises: CodeMirrorFieldBundleError: Raised if Codemirror configuration from field does not have a bundle name. Returns: string: Bundle name to load with webassets. """

    manifesto = CodemirrorAssetTagRender()
    manifesto.register_from_fields(field)

    try:
        bundle_name = manifesto.css_bundle_names()[0]
    except IndexError:
        msg = ("Given field with configuration name '{}' does not have a "
               "Javascript bundle name")
        raise CodeMirrorFieldBundleError(msg.format(field.config_name))

    return bundle_name