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Solve the following problem using Python, implementing the functions described below, one line at a time
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Description:
 def _check_suggestions(app_json, publish=False):
 """ Examines the specified dxapp.json file and warns about any violations of suggestions guidelines. :raises: AppBuilderException for data objects that could not be found """

    for input_field in app_json.get('inputSpec', []):
        for suggestion in input_field.get('suggestions', []):
            if 'project' in suggestion:
                try:
                    project = dxpy.api.project_describe(suggestion['project'], {"permissions": True})
                    if 'PUBLIC' not in project['permissions'] and publish:
                        logger.warn('Project {name} NOT PUBLIC!'.format(name=project['name']))
                except dxpy.exceptions.DXAPIError as e:
                    if e.code == 404:
                        logger.warn('Suggested project {name} does not exist, or not accessible by user'.format(
                                     name=suggestion['project']))
                if 'path' in suggestion:
                    try:
                        check_folder_exists(suggestion['project'], suggestion['path'], '')
                    except ResolutionError as e:
                        logger.warn('Folder {path} could not be found in project {project}'.format(
                                     path=suggestion['path'], project=suggestion['project']))
            if '$dnanexus_link' in suggestion:
                if suggestion['$dnanexus_link'].startswith(('file-', 'record-')):
                    try:
                        dnanexus_link = dxpy.describe(suggestion['$dnanexus_link'])
                    except dxpy.exceptions.DXAPIError as e:
                        if e.code == 404:
                            raise dxpy.app_builder.AppBuilderException(
                                'Suggested object {name} could not be found'.format(
                                    name=suggestion['$dnanexus_link']))
                    except Exception as e:
                        raise dxpy.app_builder.AppBuilderException(str(e))
            if 'value' in suggestion and isinstance(suggestion["value"], dict):
                if '$dnanexus_link' in suggestion['value']:
                    # Check if we have JSON or string
                    if isinstance(suggestion['value']['$dnanexus_link'], dict):
                        if 'project' in suggestion['value']['$dnanexus_link']:
                            try:
                                dxpy.api.project_describe(suggestion['value']['$dnanexus_link']['project'])
                            except dxpy.exceptions.DXAPIError as e:
                                if e.code == 404:
                                    logger.warn('Suggested project {name} does not exist, or not accessible by user'.format(
                                                 name=suggestion['value']['$dnanexus_link']['project']))
                    elif isinstance(suggestion['value']['$dnanexus_link'], basestring):
                        if suggestion['value']['$dnanexus_link'].startswith(('file-', 'record-')):
                            try:
                                dnanexus_link = dxpy.describe(suggestion['value']['$dnanexus_link'])
                            except dxpy.exceptions.DXAPIError as e:
                                if e.code == 404:
                                    raise dxpy.app_builder.AppBuilderException(
                                        'Suggested object {name} could not be found'.format(
                                            name=suggestion['value']['$dnanexus_link']))
                            except Exception as e:
                                raise dxpy.app_builder.AppBuilderException(str(e))