Internal function that is used for generation of the notebooks footer.

    ----------
    Parameters
    ----------
    notebook_object : notebook object
        Object of "notebook" class where the header will be created.

    notebook_file : str
        Notebook filename.

    notebook_type : str
        Notebook type: - "Main_Files_Signal_Samples"
                       - "Main_Files_By_Category"
                       - "Main_Files_By_Difficulty"
                       - "Main_Files_By_Tag"
                       - "Acquire"
                       - "Open"
                       - "Visualise"
                       - "Process"
                       - "Detect"
                       - "Extract"
                       - "Decide"
                       - "Explain"

def _generate_header(notebook_object, notebook_type, notebook_file):
    """
    Internal function that is used for generation of the notebooks footer.

    ----------
    Parameters
    ----------
    notebook_object : notebook object
        Object of "notebook" class where the header will be created.

    notebook_file : str
        Notebook filename.

    notebook_type : str
        Notebook type: - "Main_Files_Signal_Samples"
                       - "Main_Files_By_Category"
                       - "Main_Files_By_Difficulty"
                       - "Main_Files_By_Tag"
                       - "Acquire"
                       - "Open"
                       - "Visualise"
                       - "Process"
                       - "Detect"
                       - "Extract"
                       - "Decide"
                       - "Explain"

    """

    header_aux = HEADER
    header_aux = header_aux.replace("FILENAME", notebook_file.split(".")[0] + ".dwipynb")
    header_aux = header_aux.replace("SOURCE", "https://mybinder.org/v2/gh/biosignalsnotebooks/biosignalsnotebooks/master?filepath=header_footer%2Fbiosignalsnotebooks_environment%2Fcategories%2F" + notebook_type + "%2F" + notebook_file + ".dwipynb")

    if "Main_Files" in notebook_type:
        header_aux = header_aux.replace("../MainFiles/", "")

    # ================ Insertion of the div reserved to the Notebook Description ===================
    notebook_object["cells"].append(nb.v4.new_markdown_cell(header_aux,
                                                            **{"metadata":
                                                               {"tags": ["header"]}}))