class_docstr: WSGI middleware validating security on response.
  
  It validates:
  - responses have Content-Type
  - responses have X-Content-Type-Options: nosniff
  - text/html responses have CSP header. It also validates whether the CSP
    headers pass basic requirement. e.g., default-src should be present, cannot
    use "*" directive, and others. For more complete list, please refer to
    _validate_csp_policies.
  
  Instances of this class are WSGI applications (see PEP 3333).
docstr: Initializes an `SecurityValidatorMiddleware`.
  
  Args:
    application: The WSGI application to wrap (see PEP 3333).
docstr_tok: ["Initializes","an","`","SecurityValidatorMiddleware","`",".","Args",":","application",":","The","WSGI","application","to","wrap","(","see","PEP","3333",")","."]
code: def __init__(self, application):
      """Initializes an `SecurityValidatorMiddleware`.
  
      Args:
        application: The WSGI application to wrap (see PEP 3333).
      """
      self._application = application
  
file_path: tensorboard/tensorboard/backend/security_validator.py
imports: import dataclasses
  from typing import Collection
  from werkzeug.datastructures import Headers
  from werkzeug import http
  from tensorboard.util import tb_logging
label_desc: Use image node_id 1 to create a new SecurityValidatorMiddleware object  with example: obj = SecurityValidatorMiddleware(application)