code: @Beta
      public boolean isValidSection(SectionHeader header) {
          // sidenote: the readsize should never be > 0 if the section starts
          // outside the file
          // but we make sure that everything is alright
          return getReadSize(header) > 0
                  && header.getAlignedPointerToRaw() < file.length();
      }
docs: Returns whether the section is valid.
  <p>
  A section is valid if the readsize is greater than 0 and the section
  start is within the file.
  
  @see #getReadSize(SectionHeader)
  @param header
  the section's header
  @return true iff section is valid