protected function getValue(string $name) : ?string
    {
        $checkName = $this->envPrefix . strtoupper($name);
        return $this->environmentVariables[$checkName] ?? null;
    }
protected function getValue(string $name) : ?string
    {
        $checkName = $this->envPrefix . strtoupper($name);
        return $this->environmentVariables[$checkName] ?? null;
    }
protected function getValue ( string $ name ) : ? string { $ checkName = $ this -> envPrefix . strtoupper ( $ name ) ; return $ this -> environmentVariables [ $ checkName ] ?? null ; }
Reads an environment variable, taking the prefix into account.

@param string $name
The variable to read.
@return string|null
Reads an environment variable taking the prefix into account .