Illuminate\Database\Eloquent\Model::fill PHP Method

    public function fill(array $attributes)
    {
        $totallyGuarded = $this->totallyGuarded();
        foreach ($this->fillableFromArray($attributes) as $key => $value) {
            $key = $this->removeTableFromKey($key);
            // The developers may choose to place some attributes in the "fillable"
            // array, which means only those attributes may be set through mass
            // assignment to the model, and all others will just be ignored.
            if ($this->isFillable($key)) {
                $this->setAttribute($key, $value);
            } elseif ($totallyGuarded) {
                throw new MassAssignmentException($key);
            }
        }
        return $this;
    }

 /**
  * @param array $data
  * @return bool
  */
 public function insert(array $data = [])
 {
     $this->source->fill($data);
     if ($this->source->save()) {
         return $this->source->getKey();
     }
     return false;
 }