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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 ds9_objects_to_string(regions, coordsys='fk5', fmt='.6f', radunit='deg'):
 """ Converts a `list` of `~regions.Region` to DS9 region string. Parameters regions : `list` List of `~regions.Region` objects coordsys : `str`, optional This overrides the coordinate system frame for all regions. Default is 'fk5'. fmt : `str`, optional A python string format defining the output precision. Default is .6f, which is accurate to 0.0036 arcseconds. radunit : `str`, optional This denotes the unit of the radius. Default is 'deg'(degrees) Returns ------- region_string : `str` DS9 region string Examples -------- # Region file format: DS9 astropy/regions fk5 circle(1.000007,2.000002,5.000000) """

    shapelist = to_shape_list(regions, coordsys)
    return shapelist.to_ds9(coordsys, fmt, radunit)