public static ECPoint pointDecode(CurveType curveType, PointFormatType format, byte[] encoded)
      throws GeneralSecurityException {
    return pointDecode(getCurveSpec(curveType).getCurve(), format, encoded);
  }
Decodes an encoded point on an elliptic curve. This method checks that the encoded point is on
the curve.

@param curve the elliptic curve
@param format the format used to enocde the point
@param encoded the encoded point
@return the point
@throws GeneralSecurityException if the encoded point is invalid or if the curve or format are
    not supported.
@since 1.1.0
java_src/src/main/java/com/google/crypto/tink/subtle/EllipticCurves.java