How to use the envisage.plugins.python_shell.api.IPythonShell function in envisage

# Namespace contributions.
        for bindings in self._bindings:
            for name, value in bindings.items():
                self.bind(name, value)

        for command in self._commands:
            try:
                self.execute_command(command)
            except Exception as e:
                logger.exception(
                        "The command '%s' supplied to the Ipython shell "
                        "plugin has raised an exception:\n%s" %
                        (command, traceback.format_exc()))

        # Register the view as a service.
        self.window.application.register_service(IPythonShell, self)

        ns_view = self.window.application.get_service(INamespaceView)
        if ns_view is not None:
            self.on_trait_change(ns_view._on_names_changed, 'names')

        def try_set_focus():
            try:
                self.shell.control.SetFocus()
            except:
                # The window may not have been created yet.
                pass

        def set_focus():
            self.window.application.gui.invoke_later(try_set_focus)

        GUI.invoke_later(set_focus)

for name, value in bindings.items():
                self.bind(name, value)

        for command in self._commands:
            self.execute_command(command)

        # We take note of the starting set of names and types bound in the
        # interpreter's namespace so that we can show the user what they have
        # added or removed in the namespace view.
        self._namespace_types = set(
            (name, type(value)) for name, value in self.namespace.items()
        )

        # Register the view as a service.
        app = self.window.application
        self._service_id = app.register_service(IPythonShell, self)

        return self.shell.control

def run_file(self, path):
        """ Called by the server to execute a file.
        """
        shell = self.application.get_service(IPythonShell)
        shell.execute_file(path, hidden=False)

def get_shell(window):
    """ Given an application window, retrieve the ipython shell.
    """
    return window.application.get_service(IPythonShell)

def readline(self):
        pass

    def writelines(self, lines):
        for line in lines:
            self.write(line)

    def flush(self):
        pass

    def isatty(self):
        return 1


@provides(IPythonShell)
class PythonShellView(View):
    """ A view containing an interactive Python shell. """

    #### 'IView' interface ####################################################

    # The part's globally unique identifier.
    id = "envisage.plugins.python_shell_view"

    # The part's name (displayed to the user).
    name = "Python"

    # The default position of the view relative to the item specified in the
    # 'relative_to' trait.
    position = "bottom"

    #### 'PythonShellView' interface ##########################################

def create_control(self, parent):
        """ Creates the toolkit-specific control that represents the view.

        'parent' is the toolkit-specific control that is the view's parent.

        """

        self.ui = self.edit_traits(parent=parent, kind="subpanel")

        self.shell_view = self.window.application.get_service(IPythonShell)
        # 'shell_view' is an instance of the class PythonShellView from the
        # module envisage.plugins.python_shell.view.python_shell_view.

        return self.ui.control

def run_text(self, text):
        """ Called by the server to execute text.
        """
        shell = self.application.get_service(IPythonShell)
        shell.execute_command(text, hidden=False)

def _get_tree_nodes(self):
        """ Property getter. """

        shell = self.window.application.get_service(IPythonShell)

        # Cater for an un-initialized python shell view
        if shell is None:
            return NamespaceNode(value={}, readonly=True)
        filtered_namespace = dict()

        for name in shell.names:
            filtered_namespace[name] = shell.lookup(name)

        if not self.search_text == '':
            filtered_namespace = filter_namespace(filtered_namespace,
                                                        self.search_text)

        return NamespaceNode(value=filtered_namespace, readonly=True)

def create_control(self, parent):
        """ Creates the toolkit-specific control that represents the view.

        'parent' is the toolkit-specific control that is the view's parent.

        """
        self.ui = self.edit_traits(parent=parent, kind='subpanel')

        # Register the view as a service.
        self.window.application.register_service(INamespaceView, self)

        shell = self.window.application.get_service(IPythonShell)
        if shell is not None:
            shell.on_trait_change(self._on_names_changed, 'names')
            self._on_names_changed(shell.names)

        return self.ui.control

# Enthought library imports.
from envisage.api import IExtensionRegistry
from envisage.api import ExtensionPoint
from envisage.plugins.python_shell.api import IPythonShell
from envisage.plugins.ipython_shell.api import INamespaceView
from pyface.workbench.api import View
from pyface.ipython_widget import IPythonWidget
from pyface.api import GUI
from traits.api import Instance, Property, provides, Dict


# Setup a logger for this module.
logger = logging.getLogger(__name__)

@provides(IPythonShell)
class IPythonShellView(View):
    """ A view containing an IPython shell. """

    #### 'IView' interface ####################################################

    # The part's globally unique identifier.
    id = 'envisage.plugins.python_shell_view'

    # The part's name (displayed to the user).
    name = 'IPython'

    # The default position of the view relative to the item specified in the
    # 'relative_to' trait.
    position = 'bottom'

    #### 'PythonShellView' interface ##########################################