docs: def from_pandas(regs, meta=None, chr_name=None, start_name=None, stop_name=None,
                  strand_name=None, sample_name=None):
      """ Creates a GDataframe from a pandas dataframe of region and a pandas dataframe of metadata
  
      :param regs: a pandas Dataframe of regions that is coherent with the GMQL data model
      :param meta: (optional) a pandas Dataframe of metadata that is coherent with the regions
      :param chr_name: (optional) which column of :attr:`~.regs` is the chromosome
      :param start_name: (optional) which column of :attr:`~.regs` is the start
      :param stop_name: (optional) which column of :attr:`~.regs` is the stop
      :param strand_name: (optional) which column of :attr:`~.regs` is the strand
      :param sample_name: (optional) which column of :attr:`~.regs` represents the sample name
             of that region. If nothing is provided, all the region will be put in a single sample.
      :return: a GDataframe
      """
      regs = check_regs(regs, chr_name, start_name, stop_name, strand_name, sample_name)
      regs = to_gmql_regions(regs)
      if meta is not None:
          if not check_meta(meta, regs):
              raise ValueError("Error. Meta dataframe is not GMQL standard")
      else:
          meta = empty_meta(regs)
      return GDataframe(regs, meta)