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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 _BuildFindSpecsFromFileSourcePath( self, source_path, path_separator, environment_variables, user_accounts):
 """Builds find specifications from a file source type. Args: source_path (str):
 file system path defined by the source. path_separator (str):
 file system path segment separator. environment_variables (list[str]):
 environment variable attributes used to dynamically populate environment variables in key. user_accounts (list[str]):
 identified user accounts stored in the knowledge base. Returns: list[dfvfs.FindSpec]: find specifications for the file source type. """

    find_specs = []
    for path_glob in path_helper.PathHelper.ExpandRecursiveGlobs(
        source_path, path_separator):
      logger.debug('building find spec from path glob: {0:s}'.format(
          path_glob))

      for path in path_helper.PathHelper.ExpandUsersVariablePath(
          path_glob, path_separator, user_accounts):
        logger.debug('building find spec from path: {0:s}'.format(path))

        if '%' in path:
          path = path_helper.PathHelper.ExpandWindowsPath(
              path, environment_variables)
          logger.debug('building find spec from expanded path: {0:s}'.format(
              path))

        if not path.startswith(path_separator):
          logger.warning((
              'The path filter must be defined as an absolute path: '
              '"{0:s}"').format(path))
          continue

        # Convert the path filters into a list of path segments and
        # strip the root path segment.
        path_segments = path.split(path_separator)

        # Remove initial root entry
        path_segments.pop(0)

        if not path_segments[-1]:
          logger.warning(
              'Empty last path segment in path filter: "{0:s}"'.format(path))
          path_segments.pop(-1)

        try:
          find_spec = file_system_searcher.FindSpec(
              location_glob=path_segments, case_sensitive=False)
        except ValueError as exception:
          logger.error((
              'Unable to build find specification for path: "{0:s}" with '
              'error: {1!s}').format(path, exception))
          continue

        find_specs.append(find_spec)

    return find_specs