            $normalized = strtolower($header);
            if (isset($this->headerNames[$normalized])) {
                $header = $this->headerNames[$normalized];
                $this->headers[$header] = array_merge($this->headers[$header], $value);
            } else {
                $this->headerNames[$normalized] = $header;
                $this->headers[$header] = $value;
            }
        }
    }
The software constructs all or part of an SQL command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended SQL command when it is sent to a downstream component.