framework/base/Module.php
public function getVersion()
    {
        if ($this->_version === null) {
            $this->_version = $this->defaultVersion();
        } else {
            if (!is_scalar($this->_version)) {
                $this->_version = call_user_func($this->_version, $this);
            }
        }

        return $this->_version;
    }
public function getVersion()
    {
        if ($this->_version === null) {
            $this->_version = $this->defaultVersion();
        } else {
            if (!is_scalar($this->_version)) {
                $this->_version = call_user_func($this->_version, $this);
            }
        }

        return $this->_version;
    }
Returns current module version.
If version is not explicitly set, [[defaultVersion()]] method will be used to determine its value.
@return string the version of this module.
@since 2.0.11