http://www.bouncycastle.org/java.html: The Bouncy Castle Crypto package is a Java implementation of cryptographic algorithms. This jar contains JCE provider and lightweight API for the Bouncy Castle Cryptography APIs for JDK 1.5. 
public class org.bouncycastle.asn1.x509.PrivateKeyUsagePeriod extends org.bouncycastle.asn1.ASN1Encodable
  minor version: 0
  major version: 59
  flags: flags: (0x0021) ACC_PUBLIC, ACC_SUPER
  this_class: org.bouncycastle.asn1.x509.PrivateKeyUsagePeriod
  super_class: org.bouncycastle.asn1.ASN1Encodable
{
  private org.bouncycastle.asn1.DERGeneralizedTime _notBefore;
    descriptor: Lorg/bouncycastle/asn1/DERGeneralizedTime;
    flags: (0x0002) ACC_PRIVATE

  private org.bouncycastle.asn1.DERGeneralizedTime _notAfter;
    descriptor: Lorg/bouncycastle/asn1/DERGeneralizedTime;
    flags: (0x0002) ACC_PRIVATE

  public static org.bouncycastle.asn1.x509.PrivateKeyUsagePeriod getInstance(java.lang.Object);
    descriptor: (Ljava/lang/Object;)Lorg/bouncycastle/asn1/x509/PrivateKeyUsagePeriod;
    flags: (0x0009) ACC_PUBLIC, ACC_STATIC
    Code:
      stack=5, locals=1, args_size=1
        start local 0 // java.lang.Object obj
         0: .line 26
            aload 0 /* obj */
            instanceof org.bouncycastle.asn1.x509.PrivateKeyUsagePeriod
            ifeq 2
         1: .line 28
            aload 0 /* obj */
            checkcast org.bouncycastle.asn1.x509.PrivateKeyUsagePeriod
            areturn
         2: .line 31
      StackMap locals:
      StackMap stack:
            aload 0 /* obj */
            instanceof org.bouncycastle.asn1.ASN1Sequence
            ifeq 4
         3: .line 33
            new org.bouncycastle.asn1.x509.PrivateKeyUsagePeriod
            dup
            aload 0 /* obj */
            checkcast org.bouncycastle.asn1.ASN1Sequence
            invokespecial org.bouncycastle.asn1.x509.PrivateKeyUsagePeriod.<init>:(Lorg/bouncycastle/asn1/ASN1Sequence;)V
            areturn
         4: .line 36
      StackMap locals:
      StackMap stack:
            aload 0 /* obj */
            instanceof org.bouncycastle.asn1.x509.X509Extension
            ifeq 6
         5: .line 38
            aload 0 /* obj */
            checkcast org.bouncycastle.asn1.x509.X509Extension
            invokestatic org.bouncycastle.asn1.x509.X509Extension.convertValueToObject:(Lorg/bouncycastle/asn1/x509/X509Extension;)Lorg/bouncycastle/asn1/ASN1Object;
            invokestatic org.bouncycastle.asn1.x509.PrivateKeyUsagePeriod.getInstance:(Ljava/lang/Object;)Lorg/bouncycastle/asn1/x509/PrivateKeyUsagePeriod;
            areturn
         6: .line 41
      StackMap locals:
      StackMap stack:
            new java.lang.IllegalArgumentException
            dup
            new java.lang.StringBuilder
            dup
            ldc "unknown object in getInstance: "
            invokespecial java.lang.StringBuilder.<init>:(Ljava/lang/String;)V
            aload 0 /* obj */
            invokevirtual java.lang.Object.getClass:()Ljava/lang/Class;
            invokevirtual java.lang.Class.getName:()Ljava/lang/String;
            invokevirtual java.lang.StringBuilder.append:(Ljava/lang/String;)Ljava/lang/StringBuilder;
            invokevirtual java.lang.StringBuilder.toString:()Ljava/lang/String;
            invokespecial java.lang.IllegalArgumentException.<init>:(Ljava/lang/String;)V
            athrow
        end local 0 // java.lang.Object obj
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    7     0   obj  Ljava/lang/Object;
    MethodParameters:
      Name  Flags
      obj   

  private void <init>(org.bouncycastle.asn1.ASN1Sequence);
    descriptor: (Lorg/bouncycastle/asn1/ASN1Sequence;)V
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=3, locals=4, args_size=2
        start local 0 // org.bouncycastle.asn1.x509.PrivateKeyUsagePeriod this
        start local 1 // org.bouncycastle.asn1.ASN1Sequence seq
         0: .line 46
            aload 0 /* this */
            invokespecial org.bouncycastle.asn1.ASN1Encodable.<init>:()V
         1: .line 48
            aload 1 /* seq */
            invokevirtual org.bouncycastle.asn1.ASN1Sequence.getObjects:()Ljava/util/Enumeration;
            astore 2 /* en */
        start local 2 // java.util.Enumeration en
         2: .line 49
            goto 9
         3: .line 51
      StackMap locals: org.bouncycastle.asn1.x509.PrivateKeyUsagePeriod org.bouncycastle.asn1.ASN1Sequence java.util.Enumeration
      StackMap stack:
            aload 2 /* en */
            invokeinterface java.util.Enumeration.nextElement:()Ljava/lang/Object;
            checkcast org.bouncycastle.asn1.ASN1TaggedObject
            astore 3 /* tObj */
        start local 3 // org.bouncycastle.asn1.ASN1TaggedObject tObj
         4: .line 53
            aload 3 /* tObj */
            invokevirtual org.bouncycastle.asn1.ASN1TaggedObject.getTagNo:()I
            ifne 7
         5: .line 55
            aload 0 /* this */
            aload 3 /* tObj */
            iconst_0
            invokestatic org.bouncycastle.asn1.DERGeneralizedTime.getInstance:(Lorg/bouncycastle/asn1/ASN1TaggedObject;Z)Lorg/bouncycastle/asn1/DERGeneralizedTime;
            putfield org.bouncycastle.asn1.x509.PrivateKeyUsagePeriod._notBefore:Lorg/bouncycastle/asn1/DERGeneralizedTime;
         6: .line 56
            goto 9
         7: .line 57
      StackMap locals: org.bouncycastle.asn1.ASN1TaggedObject
      StackMap stack:
            aload 3 /* tObj */
            invokevirtual org.bouncycastle.asn1.ASN1TaggedObject.getTagNo:()I
            iconst_1
            if_icmpne 9
         8: .line 59
            aload 0 /* this */
            aload 3 /* tObj */
            iconst_0
            invokestatic org.bouncycastle.asn1.DERGeneralizedTime.getInstance:(Lorg/bouncycastle/asn1/ASN1TaggedObject;Z)Lorg/bouncycastle/asn1/DERGeneralizedTime;
            putfield org.bouncycastle.asn1.x509.PrivateKeyUsagePeriod._notAfter:Lorg/bouncycastle/asn1/DERGeneralizedTime;
        end local 3 // org.bouncycastle.asn1.ASN1TaggedObject tObj
         9: .line 49
      StackMap locals:
      StackMap stack:
            aload 2 /* en */
            invokeinterface java.util.Enumeration.hasMoreElements:()Z
            ifne 3
        10: .line 62
            return
        end local 2 // java.util.Enumeration en
        end local 1 // org.bouncycastle.asn1.ASN1Sequence seq
        end local 0 // org.bouncycastle.asn1.x509.PrivateKeyUsagePeriod this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0   11     0  this  Lorg/bouncycastle/asn1/x509/PrivateKeyUsagePeriod;
            0   11     1   seq  Lorg/bouncycastle/asn1/ASN1Sequence;
            2   11     2    en  Ljava/util/Enumeration;
            4    9     3  tObj  Lorg/bouncycastle/asn1/ASN1TaggedObject;
    MethodParameters:
      Name  Flags
      seq   

  public org.bouncycastle.asn1.DERGeneralizedTime getNotBefore();
    descriptor: ()Lorg/bouncycastle/asn1/DERGeneralizedTime;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // org.bouncycastle.asn1.x509.PrivateKeyUsagePeriod this
         0: .line 66
            aload 0 /* this */
            getfield org.bouncycastle.asn1.x509.PrivateKeyUsagePeriod._notBefore:Lorg/bouncycastle/asn1/DERGeneralizedTime;
            areturn
        end local 0 // org.bouncycastle.asn1.x509.PrivateKeyUsagePeriod this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lorg/bouncycastle/asn1/x509/PrivateKeyUsagePeriod;

  public org.bouncycastle.asn1.DERGeneralizedTime getNotAfter();
    descriptor: ()Lorg/bouncycastle/asn1/DERGeneralizedTime;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=1, locals=1, args_size=1
        start local 0 // org.bouncycastle.asn1.x509.PrivateKeyUsagePeriod this
         0: .line 71
            aload 0 /* this */
            getfield org.bouncycastle.asn1.x509.PrivateKeyUsagePeriod._notAfter:Lorg/bouncycastle/asn1/DERGeneralizedTime;
            areturn
        end local 0 // org.bouncycastle.asn1.x509.PrivateKeyUsagePeriod this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    1     0  this  Lorg/bouncycastle/asn1/x509/PrivateKeyUsagePeriod;

  public org.bouncycastle.asn1.DERObject toASN1Object();
    descriptor: ()Lorg/bouncycastle/asn1/DERObject;
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=6, locals=2, args_size=1
        start local 0 // org.bouncycastle.asn1.x509.PrivateKeyUsagePeriod this
         0: .line 76
            new org.bouncycastle.asn1.ASN1EncodableVector
            dup
            invokespecial org.bouncycastle.asn1.ASN1EncodableVector.<init>:()V
            astore 1 /* v */
        start local 1 // org.bouncycastle.asn1.ASN1EncodableVector v
         1: .line 78
            aload 0 /* this */
            getfield org.bouncycastle.asn1.x509.PrivateKeyUsagePeriod._notBefore:Lorg/bouncycastle/asn1/DERGeneralizedTime;
            ifnull 3
         2: .line 80
            aload 1 /* v */
            new org.bouncycastle.asn1.DERTaggedObject
            dup
            iconst_0
            iconst_0
            aload 0 /* this */
            getfield org.bouncycastle.asn1.x509.PrivateKeyUsagePeriod._notBefore:Lorg/bouncycastle/asn1/DERGeneralizedTime;
            invokespecial org.bouncycastle.asn1.DERTaggedObject.<init>:(ZILorg/bouncycastle/asn1/DEREncodable;)V
            invokevirtual org.bouncycastle.asn1.ASN1EncodableVector.add:(Lorg/bouncycastle/asn1/DEREncodable;)V
         3: .line 82
      StackMap locals: org.bouncycastle.asn1.ASN1EncodableVector
      StackMap stack:
            aload 0 /* this */
            getfield org.bouncycastle.asn1.x509.PrivateKeyUsagePeriod._notAfter:Lorg/bouncycastle/asn1/DERGeneralizedTime;
            ifnull 5
         4: .line 84
            aload 1 /* v */
            new org.bouncycastle.asn1.DERTaggedObject
            dup
            iconst_0
            iconst_1
            aload 0 /* this */
            getfield org.bouncycastle.asn1.x509.PrivateKeyUsagePeriod._notAfter:Lorg/bouncycastle/asn1/DERGeneralizedTime;
            invokespecial org.bouncycastle.asn1.DERTaggedObject.<init>:(ZILorg/bouncycastle/asn1/DEREncodable;)V
            invokevirtual org.bouncycastle.asn1.ASN1EncodableVector.add:(Lorg/bouncycastle/asn1/DEREncodable;)V
         5: .line 87
      StackMap locals:
      StackMap stack:
            new org.bouncycastle.asn1.DERSequence
            dup
            aload 1 /* v */
            invokespecial org.bouncycastle.asn1.DERSequence.<init>:(Lorg/bouncycastle/asn1/ASN1EncodableVector;)V
            areturn
        end local 1 // org.bouncycastle.asn1.ASN1EncodableVector v
        end local 0 // org.bouncycastle.asn1.x509.PrivateKeyUsagePeriod this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    6     0  this  Lorg/bouncycastle/asn1/x509/PrivateKeyUsagePeriod;
            1    6     1     v  Lorg/bouncycastle/asn1/ASN1EncodableVector;
}
SourceFile: "PrivateKeyUsagePeriod.java"