return the host name of the datanode . concode_field_sep String hostName concode_elem_sep String upgradeDomain concode_elem_sep int port concode_elem_sep AdminStates adminState concode_field_sep void setHostName concode_elem_sep int getPort concode_elem_sep AdminStates getAdminState concode_elem_sep void setUpgradeDomain concode_elem_sep void setAdminState concode_elem_sep void setPort concode_elem_sep String getUpgradeDomain
String function ( ) { return hostName ; }