def get_plain_texts(input_dict):
    """
    Widget transforms Annotated Document Corpus to string.

    :param adc: Annotated Document Corpus.
    :param feature_annotation: Select a feature annotation.
    :param delimiter: Delimiter for token concatenation.
    :param include_doc_id: Include Document Identifier.
    :return: String with all documents in Annotated Document Corpus.

    """

    adc = input_dict['adc']
    annotation = input_dict['token_annotation']
    feature_annotation = input_dict['feature_annotation']
    if feature_annotation:
        annotation+="/"+feature_annotation
    delimiter = input_dict['delimiter']
    includeDocId = input_dict['include_doc_id'] == "true"

    output_dict = {"strings": []}
    for document in adc.documents:
        output_dict["strings"].append((document.name+": " if includeDocId else "") + delimiter.join([t[1] for t in document.get_annotations_with_text(annotation)]))
    return output_dict