Firestore/src/Admin/V1/Field.php
public function setIndexConfig($var)
    {
        GPBUtil::checkMessage($var, \Google\Cloud\Firestore\Admin\V1\Field_IndexConfig::class);
        $this->index_config = $var;

        return $this;
    }
public function setIndexConfig($var)
    {
        GPBUtil::checkMessage($var, \Google\Cloud\Firestore\Admin\V1\Field_IndexConfig::class);
        $this->index_config = $var;

        return $this;
    }
public function setIndexConfig ( $ var ) { GPBUtil :: checkMessage ( $ var , \ Google \ Cloud \ Firestore \ Admin \ V1 \ Field_IndexConfig :: class ) ; $ this -> index_config = $ var ; return $ this ; }
The index configuration for this field. If unset, field indexing will
revert to the configuration defined by the `ancestor_field`. To
explicitly remove all indexes for this field, specify an index config
with an empty list of indexes.

Generated from protobuf field <code>.google.firestore.admin.v1.Field.IndexConfig index_config = 2;</code>
@param \Google\Cloud\Firestore\Admin\V1\Field\IndexConfig $var
@return $this
The index configuration for this field . If unset field indexing will revert to the configuration defined by the ancestor_field . To explicitly remove all indexes for this field specify an index config with an empty list of indexes .