def __init__(self, line_string):
        """
        To initialize a Cluster object, only a string compliant with the
        format of a cluster in an OrthoMCL groups file has to be provided.
        This line should contain the name of the group, a colon, and the
        sequences belonging to that group separated by whitespace
        :param line_string: String of a cluster
        """

        # Initializing attributes for parse_string
        self.name = None
        self.sequences = None
        self.species_frequency = {}

        # Initializing attributes for apply filter
        # If the value is different than None, this will inform downstream
        # objects of whether this cluster is compliant with the specified
        # gene_threshold
        self.gene_compliant = None
        # If the value is different than None, this will inform downstream
        # objects of whether this cluster is compliant with the specified
        # species_threshold
        self.species_compliant = None

        self.parse_string(line_string)