https://www.graalvm.org/ 
final class com.oracle.truffle.llvm.tests.interop.PyObjectTest$IntMatcher extends org.hamcrest.TypeSafeMatcher<org.graalvm.polyglot.Value>
  minor version: 0
  major version: 59
  flags: flags: (0x0030) ACC_FINAL, ACC_SUPER
  this_class: com.oracle.truffle.llvm.tests.interop.PyObjectTest$IntMatcher
  super_class: org.hamcrest.TypeSafeMatcher
{
  private final int expected;
    descriptor: I
    flags: (0x0012) ACC_PRIVATE, ACC_FINAL

  final com.oracle.truffle.llvm.tests.interop.PyObjectTest this$0;
    descriptor: Lcom/oracle/truffle/llvm/tests/interop/PyObjectTest;
    flags: (0x1010) ACC_FINAL, ACC_SYNTHETIC

  private void <init>(com.oracle.truffle.llvm.tests.interop.PyObjectTest, int);
    descriptor: (Lcom/oracle/truffle/llvm/tests/interop/PyObjectTest;I)V
    flags: (0x0002) ACC_PRIVATE
    Code:
      stack=2, locals=3, args_size=3
        start local 0 // com.oracle.truffle.llvm.tests.interop.PyObjectTest$IntMatcher this
        start local 2 // int expected
         0: .line 118
            aload 0 /* this */
            aload 1
            putfield com.oracle.truffle.llvm.tests.interop.PyObjectTest$IntMatcher.this$0:Lcom/oracle/truffle/llvm/tests/interop/PyObjectTest;
         1: .line 119
            aload 0 /* this */
            ldc Lorg/graalvm/polyglot/Value;
            invokespecial org.hamcrest.TypeSafeMatcher.<init>:(Ljava/lang/Class;)V
         2: .line 120
            aload 0 /* this */
            iload 2 /* expected */
            putfield com.oracle.truffle.llvm.tests.interop.PyObjectTest$IntMatcher.expected:I
         3: .line 121
            return
        end local 2 // int expected
        end local 0 // com.oracle.truffle.llvm.tests.interop.PyObjectTest$IntMatcher this
      LocalVariableTable:
        Start  End  Slot      Name  Signature
            0    4     0      this  Lcom/oracle/truffle/llvm/tests/interop/PyObjectTest$IntMatcher;
            0    4     2  expected  I
    MethodParameters:
          Name  Flags
      this$0    final
      expected  

  public boolean matchesSafely(org.graalvm.polyglot.Value);
    descriptor: (Lorg/graalvm/polyglot/Value;)Z
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // com.oracle.truffle.llvm.tests.interop.PyObjectTest$IntMatcher this
        start local 1 // org.graalvm.polyglot.Value item
         0: .line 125
            aload 1 /* item */
            invokevirtual org.graalvm.polyglot.Value.isNumber:()Z
            ifeq 1
            aload 1 /* item */
            invokevirtual org.graalvm.polyglot.Value.fitsInInt:()Z
            ifeq 1
            aload 1 /* item */
            invokevirtual org.graalvm.polyglot.Value.asInt:()I
            aload 0 /* this */
            getfield com.oracle.truffle.llvm.tests.interop.PyObjectTest$IntMatcher.expected:I
            if_icmpne 1
            iconst_1
            ireturn
      StackMap locals:
      StackMap stack:
         1: iconst_0
            ireturn
        end local 1 // org.graalvm.polyglot.Value item
        end local 0 // com.oracle.truffle.llvm.tests.interop.PyObjectTest$IntMatcher this
      LocalVariableTable:
        Start  End  Slot  Name  Signature
            0    2     0  this  Lcom/oracle/truffle/llvm/tests/interop/PyObjectTest$IntMatcher;
            0    2     1  item  Lorg/graalvm/polyglot/Value;
    MethodParameters:
      Name  Flags
      item  

  public void describeTo(org.hamcrest.Description);
    descriptor: (Lorg/hamcrest/Description;)V
    flags: (0x0001) ACC_PUBLIC
    Code:
      stack=2, locals=2, args_size=2
        start local 0 // com.oracle.truffle.llvm.tests.interop.PyObjectTest$IntMatcher this
        start local 1 // org.hamcrest.Description description
         0: .line 130
            aload 1 /* description */
            aload 0 /* this */
            getfield com.oracle.truffle.llvm.tests.interop.PyObjectTest$IntMatcher.expected:I
            invokestatic java.lang.Integer.valueOf:(I)Ljava/lang/Integer;
            invokeinterface org.hamcrest.Description.appendValue:(Ljava/lang/Object;)Lorg/hamcrest/Description;
            pop
         1: .line 131
            return
        end local 1 // org.hamcrest.Description description
        end local 0 // com.oracle.truffle.llvm.tests.interop.PyObjectTest$IntMatcher this
      LocalVariableTable:
        Start  End  Slot         Name  Signature
            0    2     0         this  Lcom/oracle/truffle/llvm/tests/interop/PyObjectTest$IntMatcher;
            0    2     1  description  Lorg/hamcrest/Description;
    MethodParameters:
             Name  Flags
      description  

  protected void describeMismatchSafely(org.graalvm.polyglot.Value, org.hamcrest.Description);
    descriptor: (Lorg/graalvm/polyglot/Value;Lorg/hamcrest/Description;)V
    flags: (0x0004) ACC_PROTECTED
    Code:
      stack=3, locals=3, args_size=3
        start local 0 // com.oracle.truffle.llvm.tests.interop.PyObjectTest$IntMatcher this
        start local 1 // org.graalvm.polyglot.Value item
        start local 2 // org.hamcrest.Description description
         0: .line 135
            aload 0 /* this */
            aload 1 /* item */
            aload 2 /* description */
            invokespecial org.hamcrest.TypeSafeMatcher.describeMismatchSafely:(Ljava/lang/Object;Lorg/hamcrest/Description;)V
         1: .line 136
            aload 1 /* item */
            invokevirtual org.graalvm.polyglot.Value.isNumber:()Z
            ifne 4
         2: .line 137
            aload 2 /* description */
            ldc " (not a number)"
            invokeinterface org.hamcrest.Description.appendText:(Ljava/lang/String;)Lorg/hamcrest/Description;
            pop
         3: .line 138
            goto 6
      StackMap locals:
      StackMap stack:
         4: aload 1 /* item */
            invokevirtual org.graalvm.polyglot.Value.fitsInInt:()Z
            ifne 6
         5: .line 139
            aload 2 /* description */
            ldc " (doesn't fit in int)"
            invokeinterface org.hamcrest.Description.appendText:(Ljava/lang/String;)Lorg/hamcrest/Description;
            pop
         6: .line 141
      StackMap locals:
      StackMap stack:
            return
        end local 2 // org.hamcrest.Description description
        end local 1 // org.graalvm.polyglot.Value item
        end local 0 // com.oracle.truffle.llvm.tests.interop.PyObjectTest$IntMatcher this
      LocalVariableTable:
        Start  End  Slot         Name  Signature
            0    7     0         this  Lcom/oracle/truffle/llvm/tests/interop/PyObjectTest$IntMatcher;
            0    7     1         item  Lorg/graalvm/polyglot/Value;
            0    7     2  description  Lorg/hamcrest/Description;
    MethodParameters:
             Name  Flags
      item         
      description  

  public boolean matchesSafely(java.lang.Object);
    descriptor: (Ljava/lang/Object;)Z
    flags: (0x1041) ACC_PUBLIC, ACC_BRIDGE, ACC_SYNTHETIC
    Code:
      stack=2, locals=2, args_size=2
         0: .line 1
            aload 0
            aload 1
            checkcast org.graalvm.polyglot.Value
            invokevirtual com.oracle.truffle.llvm.tests.interop.PyObjectTest$IntMatcher.matchesSafely:(Lorg/graalvm/polyglot/Value;)Z
            ireturn
      LocalVariableTable:
        Start  End  Slot  Name  Signature

  protected void describeMismatchSafely(java.lang.Object, org.hamcrest.Description);
    descriptor: (Ljava/lang/Object;Lorg/hamcrest/Description;)V
    flags: (0x1044) ACC_PROTECTED, ACC_BRIDGE, ACC_SYNTHETIC
    Code:
      stack=3, locals=3, args_size=3
         0: .line 1
            aload 0
            aload 1
            checkcast org.graalvm.polyglot.Value
            aload 2
            invokevirtual com.oracle.truffle.llvm.tests.interop.PyObjectTest$IntMatcher.describeMismatchSafely:(Lorg/graalvm/polyglot/Value;Lorg/hamcrest/Description;)V
            return
      LocalVariableTable:
        Start  End  Slot  Name  Signature
}
Signature: Lorg/hamcrest/TypeSafeMatcher<Lorg/graalvm/polyglot/Value;>;
SourceFile: "PyObjectTest.java"
NestHost: com.oracle.truffle.llvm.tests.interop.PyObjectTest
InnerClasses:
  final IntMatcher = com.oracle.truffle.llvm.tests.interop.PyObjectTest$IntMatcher of com.oracle.truffle.llvm.tests.interop.PyObjectTest