package java.lang;

import ej.annotation.Nullable;

/**
 * An element in a stack trace. Each element represents a single stack frame. All stack frames
 * except for the one at the top of the stack represent a method invocation. The frame at the top of
 * the stack represents the execution point at which the stack trace was generated. Typically, this
 * is the point at which the throwable corresponding to the stack trace was created.
 */
public final class StackTraceElement implements java.io.Serializable {

    /**
     * Returns true if the specified object is another {@code StackTraceElement} instance representing
     * the same execution point as this instance. Two stack trace elements {@code a} and {@code b} are
     * equal if and only if:
     *
     * <pre>
     *     equals(a.getFileName(), b.getFileName()) &amp;&amp;
     *     a.getLineNumber() == b.getLineNumber()) &amp;&amp;
     *     equals(a.getClassName(), b.getClassName()) &amp;&amp;
     *     equals(a.getMethodName(), b.getMethodName())
     * </pre>
     *
     * @param obj
     *        the object to be compared with this stack trace element.
     * @return true if the specified object is another {@code StackTraceElement} instance representing
     *         the same execution point as this instance.
     */
    @Override
    public boolean equals(@Nullable Object obj) {
        throw new RuntimeException();
    }

    /**
     * Returns the fully qualified name of the class containing the execution point represented by this
     * stack trace element.
     *
     * @return the fully qualified name of the {@code Class} containing the execution point represented
     *         by this stack trace element.
     */
    public String getClassName() {
        throw new RuntimeException();
    }

    /**
     * Returns the name of the source file containing the execution point represented by this stack
     * trace element. Generally, this corresponds to the {@code SourceFile} attribute of the relevant
     * {@code class} file (as per <i>The Java Virtual Machine Specification</i>, Section 4.7.7). In some
     * systems, the name may refer to some source code unit other than a file, such as an entry in
     * source repository.
     *
     * @return the name of the file containing the execution point represented by this stack trace
     *         element, or {@code null} if this information is unavailable.
     */
    @Nullable
    public String getFileName() {
        throw new RuntimeException();
    }

    /**
     * Returns the line number of the source line containing the execution point represented by this
     * stack trace element. Generally, this is derived from the {@code LineNumberTable} attribute of the
     * relevant {@code class} file (as per <i>The Java Virtual Machine Specification</i>, Section
     * 4.7.8).
     *
     * @return the line number of the source line containing the execution point represented by this
     *         stack trace element, or a negative number if this information is unavailable.
     */
    public int getLineNumber() {
        throw new RuntimeException();
    }

    /**
     * Returns the name of the method containing the execution point represented by this stack trace
     * element. If the execution point is contained in an instance or class initializer, this method
     * will return the appropriate <i>special method name</i>, {@code <init>} or {@code <clinit>}, as
     * per Section 3.9 of <i>The Java Virtual Machine Specification</i>.
     *
     * @return the name of the method containing the execution point represented by this stack trace
     *         element.
     */
    public String getMethodName() {
        throw new RuntimeException();
    }

    /**
     * Returns a hash code value for this stack trace element.
     */
    @Override
    public int hashCode() {
        throw new RuntimeException();
    }

    /**
     * Returns a string representation of this stack trace element. The format of this string depends on
     * the implementation.
     */
    @Override
    public String toString() {
        throw new RuntimeException();
    }
}