code: public String[] getHeaderValues(final String pHeaderName) {
          List<String> values = headers.get(pHeaderName);
  
          return values == null ? null : values.toArray(new String[values.size()]);
      }
docs: Gets all header values set for the given header in this response. If the
  header is not set, {@code null} is returned.
  
  @param pHeaderName the header name
  @return an array of {@code String}s, or {@code null} if there is no
  such header in this response.