class_docstr: Stores a Streamlit configuration option.
  
  A configuration option, like 'browser.serverPort', which indicates which port
  to use when connecting to the proxy. There are two ways to create a
  ConfigOption:
  
  Simple ConfigOptions are created as follows:
  
      ConfigOption('browser.serverPort',
          description = 'Connect to the proxy at this port.',
          default_val = 8501)
  
  More complex config options resolve their values at runtime as follows:
  
      @ConfigOption('browser.serverPort')
      def _proxy_port():
          """Connect to the proxy at this port.
  
          Defaults to 8501.
          """
          return 8501
  
  NOTE: For complex config options, the function is called each time the
  option.value is evaluated!
  
  Attributes
  ----------
  key : str
      The fully qualified section.name
  value : any
      The value for this option. If this is a complex config option then
      the callback is called EACH TIME value is evaluated.
  section : str
      The section of this option. Example: 'global'.
  name : str
      See __init__.
  description : str
      See __init__.
  where_defined : str
      Indicates which file set this config option.
      ConfigOption.DEFAULT_DEFINITION means this file.
  is_default: bool
      True if the config value is equal to its default value.
  visibility : {"visible", "hidden"}
      See __init__.
  scriptable : bool
      See __init__.
  deprecated: bool
      See __init__.
  deprecation_text : str or None
      See __init__.
  expiration_date : str or None
      See __init__.
  replaced_by : str or None
      See __init__.
  sensitive : bool
      See __init__.
  env_var: str
      The name of the environment variable that can be used to set the option.
docstr: Get the value of this config option.
docstr_tok: ["Get","the","value","of","this","config","option","."]
code: def value(self) -> Any:
      """Get the value of this config option."""
      if self._get_val_func is None:
          return None
      return self._get_val_func()
  
file_path: streamlit/lib/streamlit/config_option.py
imports: import datetime
  import re
  import textwrap
  from typing import Any, Callable, Optional
  from streamlit import util
  from streamlit.case_converters import to_snake_case
  from streamlit.errors import DeprecationError
label_desc: Use image node_id 4 for calling the ConfigOption obj's underlying member method code with example usage: obj.value() and returns: self, None