src/main/php/Properties.php
public function keysForSection(string $section, array $default = []): array
    {
        if (isset($this->propertyData[$section])) {
            return array_keys($this->propertyData[$section]);
        }

        return $default;
    }
public function keysForSection(string $section, array $default = []): array
    {
        if (isset($this->propertyData[$section])) {
            return array_keys($this->propertyData[$section]);
        }

        return $default;
    }
public function keysForSection ( string $ section , array $ default = [ ] ) : array { if ( isset ( $ this -> propertyData [ $ section ] ) ) { return array_keys ( $ this -> propertyData [ $ section ] ) ; } return $ default ; }
returns a list of all keys of a specific section

@api
@param   string    $section  name of the section
@param   string[]  $default  value to return if section does not exist
@return  string[]
@since   4.0.0
returns a list of all keys of a specific section